He is "not" the protagonist in Antim. Although I wished for the character to be part-antogonist but Bollywood has made it clear, it wouldn't have the guts to offer him such role and even convince him to do it. Antim is still Aayush's film, just because it's Salman, they have added an one on one action scene and a song for Salman. It is still an extended appearance, similar to Pathan.
Anyways, confirmed projects post Radhe are,
Antim [Extended special appearance]
Pathan [Extended special appearance]
Tiger 3
KEKD
Kick 2 is again put on hold. Inshallah got shelved the moment SLB went ahead shooting Alia Bhatt portions without Salman's consent and both SLB + SK not able to zero in on the money involved. SLB made Gangubai hurriedly to compensate Alia's date and also to prove a point. Inshallah for now is not happening, it has dented Salman-SLB friendship, hope it is repairable and not gone the extreme way.
Sher Khan is just for namesake because he has the unfinished script and the title locked. It isn't happening.
Salman's new film announcement will happens once he completes few schedule of Tiger 3. We can accept the new film announcement before he starts filming KEKD.