I do not think this alone will lead to the fragmentation of Ethiopia, but it will bring about more instability and chaos, then the army will stabilize things albeit forcefully and only temporarily.
Ethiopia has many internal and external actors with their own, and more often than not, contradictory interests:
Egypt.
TPLF.
Amhara extremist/unionist-ultra nationalists.
Oromo nationalists.
Abiy Ahmed and his govt.
etc...
How is the situation in the Amhara region economic-wise? Are most people living below the poverty line?
I mean, they are as poor as the rest of Ethiopia, for the most part; but they have a good amount of resources, and their region gets the most rainfall per year. they could be a richer region for sure, but their elites, like elites of the other regions, focus more on power and wealth of their own cliques,