Nope the name Loma was given to him a while back. And I think it’s you who wants to give me a pet name! You seem to have a little crush here. Lol
A is feminine, O is masculine. It's just in that sense natural to call him "Lomo" as opposed to "Loma." Whenever I hear or read "Loma," I think of a woman.
st louis blues fans somehow call Alex pietrangelo, petro. you would think it should be pietra, pietro, or petra, not petro.
In Russian a-ending is typical for familiar form of male names. (Alexandr->Sasha) and for male nicknames too. In Ukrainian it's more complicated but modern usage leans to a-ending in the last name-based nicknames (Shevchenko->Sheva)
Lomo sounds like an insult, and knowing you pathetic cretins,you are simply justifying Lomo to insult Lomachenko. Shame on you. Would you call Povetkin” Sasha “ Sasho? Didnt think so.