He'll flip ya...Flip ya for real...
I was latecomer to Birthright. Introduced by an older gamer who was a big fan. I loved the domain play it reminded me of a mashup of Diplomacy and Game of Thrones. That might send a lot of folks running lol!I say this completely seriously- outside of this website, I have never seen any Birthright love.
That's not to belittle it- but the setting only existed during one of the strangest periods of D&D- late period, near-death 2e.* And never had any products that I know of outside of that brief period (so nothing during the WoTC period). Birthright is somewhat obscure IMO (not "Pelinore" obscure!) and doesn't seem to have the same web community as 2e settings like Dark Sun or Planescape.
That said, it appears to have inspired some fierce devotion, and I always hope that fans get what they want!
*ETA- I would also stipulate that late period 2e, specifically '95-'03, was my period of absolute least involvement with any TTRPGs, so it could be that as well.