The first hijrah was not Ethiopia, it was either Dakhlak Island off the coast of Eritrea or Zayla Northern Somalia both served as entrepoints to Islam, from which it first disseminated.
They certainly did not go to Axum which was landlocked at the time and seized to exist basically.
This misperception whitewashes the reality of medieval Ethiopia which was a crusading feudal fiefdoms that hated Islam , heck any sect that was different even as you seen with Falasha. They wouldn't give anyone refuge, as they were even oppressive to their own people.
Ethiopians were religious crusaders, the prophet wouldn't send them there. How would he send them to the people who would destroy the Kaaba?
And Most of Eritrea and Somalia was not a province of Ethiopia. This also comes from a misperception with the use of Habash which was a regional name that sometimes even stretched to Egypt, Sudan to Somalia. When medieval Arab geographers and writers employed it , they were not talking about the modern supra-ethnicity ''Habesha''.
Also comes out of their fiction epic chronicles of their Kings , when in reality they never extended to rule any of those places.
We've been seperate, nor it is the longest continues country either, not only are they not a continuation Axum which had its center base in the Northern Highlands and Eritrea and spoke Geez.
But Ethiopia as a country is largely a colonial creation, where colonialist such as France/Britain/Italy ceeded territories to them. Here is a map that shows the extent of their territory, with the exception of Harar with British protection, they failed to gain control of Ogaden, were defeated each time and only incorporated pockets of Oromo areas into their realm.
Also look the delusional claim their Kings were making lool, even Eritrea was not in their control.
What we should do is open them up to the reality how things was during the medieval until the present day, it will help integrate the region more and allow people to shed off bad baggage and animosity and make way for cooperation. They also need to critically examine their culture
Somalis will have the same homework. I don't point these things out to humiliate or be mean to Ethopians.
Also being landlocked isn't not the issue, i pointed out that lots of countries that are landlocked and are doing fine. Same in for kingdoms in the past,: