Gustav?
Wich was codename for the game?
It would be really weird if somebody found out their female elf wasn’t named what they entered in the character creation screen, but was actually Gustav.
The reason the Voice Actors didn’t know Tav’s name is because Tav doesn’t have a canonical name, so “Tav” doesn’t appear anywhere in the script.
If you are suggesting that the custom created character might have a secret name other than what we enter, no, that won’t be a thing.
But I’m not really sure what this topic is about.