Koepp agrees that it would be crazy not to take into account star Harrison Ford’s real age for this next installment. In fact, he suggests that if it were not in the script, Ford would likely insist on references to this being added.
As much as he is a fan of Indy lore, Koepp says it’s essential to discard that point of view when tapping out further adventures. “You can’t write a fan script,” he insists. “You have to pretend that this movie exists without the other one.” “The worst thing to do would be to have him make reference to things he said in the first movie, like to pun on lines of dialogue.”
You can read the full interview at the link above.