Concept are is not infinitely concept though, it eventually becomes official. Notice that the final concept of Lupin ended up being what we got

Also notice the level of detail is similar to that of the "last" male Viera concept
It's not in those random unfinished "bust" versions.
The detailed version is what would get approved into the game, as that Lupin slide shows.
As for the rest of your statement; I clearly explained why the company would craft a carefully crafted written letter to present to the community. It went through PR, Marketing, and corporate before being put out; so that it would be vetted. If the decision to add hrothgar was so clear it wouldn't have taken them 2 months to craft a reasoning, much less having to present it in written form.
The reasoning they give didn't even make much sense, they talk about adding variety, but wasn't Au ra that variety already? It was the dev's chance to add whatever kind of race they ever wanted. To sacrifice the male side of Viera like that was no accident, it was an opportunity which presented itself starting with the Blizzcon debacle and terrible expansion, the closing of Guild wars 2, and the stagnation of Elders scrolls.
If you don't see the holes in their reasoning then that's on you, I see them clearly.