Even if he magically developed a jumper (which he wont) this dude is a fukking write off at this point.
You really wonder if the weight was the sole factor that did him in or was is a combo of that and him jumping all over the damn place, landing however and then having poor recovery habits when he wasn’t playing/practicing.
I would say his Weight is the contributing factor from the stress load, but maybe not wearing the proper shoes/athletic inserts? I know people are making Greg Oden comparisons, which is fair, but Oden's thing was his knee.
This is Zion's toes, so you add in his Weight (x) Torque (his toes having to shift position when he makes a cut), and without proper recovery tactics, this is sort of like Derrick Rose to a degree; where Rose's ACL injury was a hidden aspect that was going to happen because of his style of play.
I couldn't blame Zion to a fault, because when you think of career-ending/hall-of-fame shifting in Basketball you think of ACLs, you think of Achilles Injuries, Etc. You never really think of your toes just taking it all away, but in the case of Zion, this is now happening to him, and the last thing you need is to gain weight to fukk up your post-surgery rehab; in which is on him.
So TL;DR, I believe Zion's style of play is catching up to him, in that his body is just not meant for it and/or he has a very, very poor post-game recovery plan.