We do have people of African background who speak fluent Russian here. A relative of mine married one such when she was in university.
We also have a family of African background who attend our parish who are fluent in Ukrainian.
A number of Ethiopians have joined the OCA in one parish with a priest who is very accommodating to the various groups he serves there: Russian Jewish converts to Orthodoxy (who form their own sub-group in that parish), some Old Believers who have joined the OCA and also some Ethiopians.
I gave Father an Ethiopian priestly miter I once came across and he keeps it out when his Ethiopian flock attend Confession. He says it makes them feel at home!
Alex