What does the modern Halacha says about Barya Falasha (Slaves and decedents of slaves who had made giyur)

I was reading about Barya , which are direct slaves who made gyur or their descendants from the Nara People. I was surprised to learn that even after giyur they had not been released nor their children can marry Jews in Ethiopia. Nor that they had not become slave free after six years ?

What does the modern Halacha says about them ? Is that only a thing of that Eda where there are different levels of giyur ? How other denomination look on that and treat these people ?

Long text about it:

Hebrew , ( google translate about it – Google translate the word ברייה /Barya as a creature which make it more harsh than it is already is )

Edit:

Slavery in Ethiopia had been abolished finally in 1942.