Personally, I'm fine with the new races being added as is, because I dont care about new races at all. I found the perfect race and the perfect character for me and nothing they can add would make me change Vidu.
As a more general answer: I think they didnt add the Lupin (wolf people from SB) as a playable race because they are to different from humans in some aspects to make all the gear fit - specially the feet, hands and obviously the head, which wouldnt work with any helmets. Now I know that neither Hrothgar nor Viera are going to be able to wear most headgeard in the game, but I'd imagine that not only was the development of a new race out of the question for SB but also that the decision to create races that cant wear every helmet was born out of need and not wish. Maybe this is wishful thinking on my part, but I'd like to imagine that they didnt went into making those races, knowing that they'd cut the headgear but that that was rather a last resort solution ("Okay, if the only way we can get this to work in time is not re-model all the helmets... we'll do it, but we're not happy" - something along those lines)
At that point - or rather past SB - the Lupin were already established as a Beast Tribe race though, they have lore and they're not new and exciting anymore - so not only would they need to retcon and adjust some of the Lupin-lore to make them playable, but their "new race"-reveal would also only be "btw, you can play this race we've established 2 years ago in a totally different way now".
On top of that the Hrothgar are getting various different face-types - and they're far from looking like your kitty-cat aswell. So I dont see much of an issue...
If two cat-like races are to much cat for you, how do you feel about having basically 4 human-like races? Hyur, Elezen, Lalafell and Roegadyn are all basically human after all! (If you compare the Hrothgar to Mi'qote just because they both have fur, a tail and some cat-features, I can safely compare Hyur to Roegadyn because they have basically human proportions and faces)