I think restricting species for certain games is a good idea for (open) mini campaigns, where a dm has a spec. setting in mind … or at least re-flavour species so they fit into that campaign’s frame
(e.g. reflavoured species for the Primal open table).
When most players hop from VALUE table to VALUE table often with different dms, restricting everything to one setting feels a bit harsh. Esp. considered we chose not to restrict ourselves to only run official adventures.
Restricting stuff that had been published only online via DNDBeyond (e.g. Astarion’s Book of Hunger), is something I can behind though 
… since this would otherwise confuse dms who do not use this platform and just consult books.
(was not mentioned yet, I just had the idea when reading the posts above)
That being said just for my pers. statistics, the bigges % of the games I ran and joined as a player in the last season where either set in Eberron or were set in homebrew settings.
There were only 2 Faerûn games, and 1 Strixhaven game. Others were just “generic fantasy land”.
… but I agree, that dep. on the location you play in and the dms/tables you join, this could be vastly diff. experience on how many % of Faerûn adventures a player experiences.
edit:
Setting wise - there is a new Ravenloft book coming out and if rumours are true there will be a Dark Sun 
book later this year … so plenty of more worlds to explore 