It's literally what was posted on these forums, people weren't going off some vague third party translated source no one is able to find anymore.
Now this was of course after the expansion had released so while the original intent may have been to never add more hairstyles to them, I personally don't remember ever reading anything like that from an officially translated source and the LL a month or so later immediately contradicts that as well.
Over time there's also been a lot of talk about how the questions would often lump Viera and Hrothgar together even though they had very different problems that needed different solutions, and we'd get one non-specific answer so it was never really clear if it was meant for Viera, Hrothgar or both.
Your point still stands though, if they had been clear before Hrothgar came out that they had no intent or they'd be unable to add more hairstyles to them then people could have made an informed decision on playing the race or not. It would still be a strange decision to release a race with effectively 2 hairstyles per head you can't even change between without a Fantasia and then not add anything to them, but if they go back on their alleged original intent for the race a month or so later they can't act surprised people want more hair.
It seems the options now are;
A) Faster shared hairstyles with no ears.
B) Slower shared hairstyles with ears.
C) Unique racial hairstyles but fewer in number.
I don't envy them having to sift through all the feedback and having to try and make a decision that will make the most people happy, but they really kind of did it to themselves being so unclear from the start. I feel worse for Hrothgar players who for the most part waited patiently and now have to wait even longer for a solution.
I wonder if all this was communicated to the JP playerbase more clearly before release?