I dont know why they changed the names, the ones they used first were perfectly fine! Besides if i was looking for a spy the last name 'forger' would probably pique my curiosity.
First, it is important to look at the raws for the Japanese chapters, which do include English spellings.
Yor Briar. Loid Forger. Ania. These are the spelling that is intended by Endo-sensei.
I’m not sure if this would end up changing if we were to get an anime adaptation or a physical English volume, but those are the canon spellings.
Why do the translators keep mixing up the spellings?
I know that the difference between Folger/Forger and Yor/Yoru and has to do with the fact that the Japanese language has different sounds compared to English. In Japanese there isn’t a clearly different sound for R and L like in English.
For instance, from bnha, All Might is spelled with Romaji as Ōru Maito. Notice the R vs the L. And the hero Rock Lock’s name is spelled Rokku Rokku. And with the hero Mirko, her Romaji spelling is Miruko. Like Yor vs Yoru. Something to note, though, is that in all these cases, the u sound isn’t there when translated into English.
Forger and Folger are both real last names, so I can see why the translators might have been unsure with which spelling to use if they had ignored the English that was present in the raws and only focused on translating the Japanese speech bubbles.
I think one of the reasons Forger was ultimately chosen by the translators is because it gives a clue to the fact that the Forger family is a fake family. It’s a pun, a joke, that’s the point.
Often in manga names have significance to the characters. For example. BNHA all of the character’s names in Kanji are a pun centered around their Quirk or personality or backstory.
As for Loid vs Lloyd and Ania vs Anya, I think Endo-sensei decided to use European-esque spellings. Ania seems to be is a Russian spelling, which makes sense to me, since the plot and world building of this story reminds me vaguely of Soviet Russia and the Cold War era.
I personally don’t mind the new spellings, but I’d like for the new translations to stay consistent.