So, here's a separate thought, as I ponder whether Han Solo (or any of the other OT heroes, for that matter) will be killed in the new Star Wars movie.
When you're doing a story that is about a hero, especially one like the Indy films, I don't actually want to watch my heroes get old and decrepit and/or die. I want to see them ride off into the sunset, still relatively youthful, and that's how I'll remember them.
There's this impulse, this drive in Hollywood now to NEVER EVER LET THE STORY END. Fundamentally, I think this really, really hurts good storytelling. Think about it. When you tell a child a bedtime story and say "The end," and the kid says "And then what happened?" first, you don't want to answer because your kid is probably just trying to buy time before you turn off the lights. But, second, the answer is, eventually, "Nothing. They died. Go to sleep."
Now, think about this. Do you really want that to be the answer to "and then what happened" for your heroes? I don't. Unless it's some noble sacrifice or grand standoff or whathaveyou, I don't want my heroes to wither and die. But continuing to put Ford into this action-punchy-shooty-tough-guy role...it's just not what I want to see at all. On the other hand, I don't really want to see anyone else playing Henry Jones, Jr. aside from Ford. Not at this point. YIJC is fine for what it is, but I don't want that for my Indy films. I never even wanted KOTCS, really, and although I own a copy of it, I've literally never used the disc as anything other than a coaster. The Indy trilogy ends perfectly. Hollywood's desire to provide an answer to "And then what happened?" shouldn't be applied to all franchises.
It works great for superheroes, because superheroes live in a kind of unreality the way James Bond does (although, side note, I'd LOVE to watch James Bond die only to be succeeded by...James Bond, a la the "It's a code name" theory.). But Indy's always been a little different in that respect. By having one guy play one role for over 30 years, they're basically locked into Ford = Indy. And Ford = +70, which does not make for a compelling, believable action hero no matter how tough he is.
It's time to let this franchise go, folks, or do the "hand-off" film if you absolutely MUST make more.