Unfortunately Larian has been super hush hush about what races will be in the final game. Likely because they themselves don't actually know. I imagine they'd like to get all the playable races from 5e in, including Volo's Guide races and such, but that would be pretty much impossible. Or at least need extensive DLC.
So they need to be selective and haven't figured out exactly what will get in.
Tabaxi aren't an impossibility, but I'd rank them as fairly low on the priority list as far as which races are likely to get in.
