Simmons had already been selected number one before he got hurt so not really the same thing.
It's analogous, they'll take Zion and have him sit his rookie year worst case
Yeah, It's not really the same as Simmons. If it's a serious enough injury to put him on the shelf the rest ofthe year, Embiid and Michael Porter are closest I can think of. Kyrie also only played in about 10 games his year at Duke, but he did come back in time for the tournament, so I think he still went number 1.
A more extreme example is the running back the Niners picked (Lattimore - I think) that had a pretty horrific knee injury (Willis McGahee too) and fell to the point where he was a mid round pick. Not a doctor, but Zion's injury didn't look that bad. I'd bet he's back this year and still the number 1 pick.
For some reason, I think he's the kind of guy that is more interested in trying to play for a NC than sitting out and counting his millions, which he's still going to get.