There’s a wealth of story potential in the Top Gun universe if director Joseph Kosinski chooses to bring Iceman back, so leaving Kilmer’s fan-favorite character on the table (particularly when he has expressed interest in returning) seems like a wasted opportunity.
Iceman played a central role in Maverick’s character arc throughout the first film’s storyline, and he helped fill the void left by Goose by the time the credits rolled on the original.
Despite the fact that Val Kilmer’s comments in his recent Reddit AMA session don’t confirm whether or not he’s involved in Top Gun: Maverick, it would be hard to imagine a version of that universe without him.