Feel free to wish for new settings.
My point, however, is to not do so in conjunction with wishing for a new Birthright.
1) the setting was the weakest point of Birthright (imo)
2) the setting is arguably not even the point of Birthright, the domain layer (including heroes and awnshegn as their rulers) is
and last but not least
3) WotC will never commit to a new setting that isn't Forgotten Realms anyway (except as stand-alone supplements that aren't then supported going forward)
So, again, nothing wrong with asking for new settings. But that wish should not automatically be intertwined with the desire for a new Birthright
As I see it, making Birthright an overlay on top of Forgotten Realms gives the greatest chance of making it last, and become truly integrated into WotCs core lineup