This hadith didn't mention they would extinct but infact be mixed but still hold tradition.
What is written cannot be unwritten.
The Prophet (peace_be_upon_him) said: There will be civil strife which wipe out the Arabs, and their slain will go to Hell. During it the tongue will be more severe than blows of the sword. *sunan Abu dawud book 4252
Narrated Abu Hurairah:
The Prophet (peace_be_upon_him) said: Woe to the Arabs because of the evil which has drawn near! He will escape who will restrain his hand.
( sunan Abu dawud book 30. 4237)
*Umm Sharik reported: I heard Allah's Messenger (may peace be upon him) as saying: The people would run away from the Dajjal seeking shelter in the mountains. She said: Where would be the Arabs then in that day? He said: They would be small in number. Muslim: Book 41, Number 7035:
Narrated Abu Bakrah:
The Apostle of Allah (peace_be_upon_him) said: There will be a period of commotion in which the one who lies down will be better than the one who sits, and the one who sits is better than the one who stands, and the one who stands is better than the one who walks, and the one who walks is better than the one who runs (to it).
He asked: What do you command me to do, Apostle of Allah? He replied: He who has camels should remain with his camels, he who has sheep should remain with his sheep, and he who has land should remain with his land.
He asked: If anyone has more of these, (what should he do)?
He replied: He should take his sword, strike its edge on a stone, and then escape if he can. *sunan Abu dawud book 30, 4243
Narrated Sa'd ibn Abu Waqqas:
I asked: Apostle of Allah! tell me if someone enters my house and extends his hands to kill me (what should I do?) The Apostle of Allah (peace_be_upon_him) replied: Be like the two sons of Adam. The narrator Yazid (ibn Khalid) then recited the verse: "If thou dost stretch they hand against me to slay me." *sunan Abu dawud book 30 4244
Narrated Abdullah ibn Mas'ud ; Khuraym ibn Fatik:
The tradition mentioned above (No. 4243) has also been transmitted by Ibn Mas'ud through a different chain of narrators.
Ibn Mas'ud said: I heard the Prophet (peace_be_upon_him) say: He then mentioned a portion of the tradition narrated by Abu Bakrah (No. 4243).
This version adds: He (the Prophet) said: All their slain will go to Hell. I (Wabisah) asked: When will this happen Ibn Mas'ud?
He replied: This is the period of turmoil (harj) when a man will not be safe from his associates.
I asked: What do you command me (to do) if I happen to live during that period? He replied: You should restrain your tongue and hand and stay at home.
When Uthman was slain, I recollected this tradition. I then rode (on a camel) and came to Damascus. There I met Khuraym ibn Fatik and mentioned this tradition to him. He swore by Allah, there was no god but He, he had heard it from the Apostle of Allah (peace_be_upon_him), as Ibn Mas'ud transmitted it to me (Wabisah). *sunan Abu dawud book 30 4245
Narrated Abu Musa al-Ash'ari:
The Apostle of Allah (peace_be_upon_him) said: Before the Last Hour there will be commotions like pieces of a dark night in which a man will be a believer in the morning and an infidel in the evening, or a believer in the evening and infidel in the morning. He who sits during them will be better than he who gets up and he who walks during them is better than he who runs. So break your bows, cut your bowstrings and strike your swords on stones. If people then come in to one of you, let him be like the better of Adam's two sons. *sunan Abu dawud book 30 4246
Narrated Abu Hurairah:
The Prophet (peace_be_upon_him) said: There will be civil strife (fitnah) which will render people deaf, dumb and blind regarding what is right. Those who contemplate it will be drawn by it, and giving rein to the tongue during it will be like smiting with the sword. *sunan Abu dawud book 30 4251
Narrated Abdullah ibn Amr ibn al-'As:
The Prophet (peace_be_upon_him) said: There will be civil strife which wipe out the Arabs, and their slain will go to Hell. During it the tongue will be more severe than blows of the sword. *sunan Abu dawud book 4252
Abu Dawud said: Al-Thawri transmitted it from Laith, from Tawus on the authority of al-A'jam.
Narrated Abu Sa'id al-Khudri:
The Apostle of Allah (peace_be_upon_him) said: A Muslim's best property will soon be sheep which he takes to the top of mountains and the places where the rain falls, fleeing with his religion from civil strife (fitnah). *sunan Abu dawud book 30 4254
Narrated Ahnaf b. Qais:
I came out with the intention of (participating in) fighting. Abu Bakrah met me and said: Go back, for I heard the Apostle of Allah (peace_be_upon_him) say: When two muslims face each other with their swords, the killer and the slain will go to Hell. He asked: Apostle of Allah, this is the killer (so naturally he should go to the Hell), but what is the matter with the slain? He replied: He intended to kill his companion. *sunan Abu dawud book 30 4255
This mean't the pure Arabs (Qahtani, Adnani (even though they are mesopatemian descent)) will be little due to conquering and spreading islam like to persia, eygpt, Soain, Uzbekistan, india, Somalia and more places, but they are so many that call themselves as Arabs but have been correct. A person who is Arab is the person who speaks Arabic. A white man can be Arab by speaking Arabic according to uluma.
This hadith says that the prophet’s face was flushed. In fact, this state was activated due to the evil and terrifying results of that tribulation which had been shown to him by Allah almighty. Secondly, the reason the Prophet recited la ilaha illallah is that he wanted to show surprise and seriousness of the matter. Thirdly, the Messenger of Allah warned the Arabs giants a great danger that is lurking at their doors. He did so in order to divert the attention of the Arabs to this fast-approaching peril, which they are inadvertent to, lest they may overtake and destroy them and so that they adopt sufficient precautions to guard themselves against it.
The prophet has mentioned the Arabs only in this hadith but in fact he has meant all the Muslims. Since Islam was practiced mostly in Arab countries those days, the Messenger of Allah has especially mentioned the Arabs by name, otherwise all the Muslims must be careful about this tragic prophecy.
Which thus means that the hadith refer to all muslims.
The hadiths you brought is not talking about the Arabs but all muslim because at the time islam was in Arabia, these hadiths talk about the major signs of the day of Judgment, which thus refers to the muslims around the earth.