I think his game will age well... He doesn't rely on athleticism, he's not uber quick, but he relies on specific timing, and using his wingspan/strength well.
His passing is slightly inflated due to the great shooters, but he handles the ball well enough to be able to push the fast break. I think he will always be above average passer for his position, and average like 4-6 APG easily.
Super max? Well, that's a little ridiculous to expect that. Curry is worth the supermax. Durant is worth the supermax. Klay? Maybe... But you would be hard pressed to be able to find anyone that can replicate what Draymond brings. I would argue that Draymond and Klay are equally as important, and that with the arrival of Durant. It all leads to prove that keeping Draymond should be more valuable than Klay, due to how much their defense will decline. I'm not convinced Bell can even produce half of what Draymond can do, but Bell is certainly in line to be the successor. Question remains, if he can still even bring to the table what Dray can bring.
That being said, there is a lot of hate for Dray. I still like him, even though he's dirty, talks a lot of trash. He reminds me of how I felt about Joakim Noah. Hated him, but my god Noah in in 2010-2012 would've been perfect on our team.