The Mouse House has bought Marvel, Lucasfilm, and, now, Indiana Jones. I wonder if it's becoming a one-company bubble.
But I think in order to be safe they need to make the movies prequels to Crystal Skull, that way there's no need to try to get Shia back or recast the role of Indy's son, there's potential to have some characters from the earlier movies who weren't accounted for in Crystal Skull