Considering that the Kinder (ugh) are now in playtesting; I think Dragonlance is pretty much assured. I'd like it if Dark Sun got a new book but they've got to finish the 5e Psion first.
Since Marvel probably won't be out of beta until 2023, I nominate the Transformers RPG. https://www.amazon.com/Renegade-Transformers-RPG-Core-Rulebook/dp/1736884336