this shouldve been Seans last film :(
the reason why it wasnt is here:
https://www.express.co.uk/entertainment/films/907548/Sean-Connery-Indiana-Jones-4-Kingdom-of-the-Crystal-Skull-Harrison-Ford-Steven-Spielberg
he would only have been about 76/77 when filming - younger than Ford will be when he does Indy 5!
It was kind of wrong to kill him off screen anyway when Connery was still alive and kicking.. at least have them thinking he's dead or missing presumed dead then he turns up near the end.. or a fun cameo right at the end with the wedding reminiscent of the last scene of the Costner Robin Hood
Maybe they plan to use him in Indy 5 for a CG deaged flashback scene (as Sean was/is such a big part of the Indy mythos)