If Steichen leaves, it won't affect Jalen Hurts at all since the head coach is Nick Sirianni, an offensive guy, so Hurts will essentially be in the same offensive system as long as Sirianni is still there. If I am a team with a young QB and you need a head coach, an offensive coach is preferable, because then if the OC under that offensive head coach becomes a head coach himself, there's still continuity in that offense and helps that young QB grow.
There's also Sean Payton out there, who is basically taking a year off. I get the feeling that he would only come back if there's already an established QB. Like if the Chargers choke again and Brandon Staley doesn't make it to a third season, Peyton might be tempted to stay in LA to coach Justin Herbert. Or he goes to Arizona to try to unleash Kyler Murray's potential. I don't think he goes anywhere that has no QB already in place but I could be wrong. Steichen is basically "Plan B" in case Sean Payton doesn't work out.