It'd be ideal for them to release 2 races, however Hrothgar remain an enigma and there's an awful lot of body types which either race could fit.
I would not be disappointed if they enabled Hrothgar to feature faces like Byakko's, maybe with a body type similar to an au ra's or highlander's. I don't believe they will make them too similar to roegadyn, both because of that race's % of characters played but also because they'd probably want to distinguish it physically.
For Viera, I do like the official concept art they have put forward, but something like this would work (albeit I think it's consistent with the concept art):
They do need to eventually re-visit the older races and broaden the customization options, since some of the issues appear to arise due to limited customization options for them, or design flaws, like the awkwardness in elezen models.