I'm going to paraphrase someone else's point I saw in a similar discussion last night, but this is how I expect things are happening right now:
Viera and Hrothgar both need major overhauls. SE is aware of this. People are angry and they know it. But anything they do right now, such as making one individual hairstyle or helm work for Viera/Hroth, would be akin to putting a bandaid on a stab wound. Likely what's happening is they're working to prepare a major overhaul to reveal for Endwalker, and allocating extra resources for short-term fixes that they would end up overwriting with major overhauls anyway would be costly both on a human labor level and on a financial one.
Maybe this is an overly optimistic viewpoint on the whole situation, but this is most likely what's going on. From an operations-and-development perspective, it's the route that makes the most sense. Are people going to be fuming in the meantime as they continue to get the shaft while other players get to wear the shiny new hair and helms? Of course they are, and rightfully so. Viera and Hroth were rolled out half-finished, and it shows. But all SE can do now is fix the mistake they made in the most efficient manner as possible. I for one would rather them do it this way, than make a bunch of patchwork fixes that are disjointed and half-hearted, anyway.
(Addendum, because I know it's going to come up: If that major overhaul includes male Viera and female Hroth, great! That would be fantastic and make many, many players happy. If it doesn't include that, I'll just be glad to see them brought up to the same standards as the other races.)