As much I love Sallah and Short Round, I don't see the point in bringing these characters back unless they were an integral part of the plot. We've seen what happens in the previous films when they try to bring favorite characters back. It just doesn't work as well.
Sallah returned for Last Crusade but in that movie he was basically a goofy caricature of himself arguing with Indy about camels and compensation. However, on a side note I think it would be funny if they have a scene where we actually get to meet his brother-in-law and he's played by Danny DeVito. DeVito as you know was originally considered for the Sallah character.
But I would rather see Indy be on a a new adventure with new sidekicks that we haven't met yet. I mean the guy has been on adventures for half a century, Sallah, Shortround and Mac can't be the only friends he has in the business.