IHSAA deems Summer completely voluntary activity.
So July 31st, that Monday is the date to keep in mind: If all systems go then season goes in as is, maybe with less summer time to prepare, but again, IHSAA looks at that completely separate.
If schools/state still are closed up for on site participation by July 31st then you can see some issues to come around. You need 10 practices (1 a day) to participate in any game, among other stuff, but as far as 21 practices, that is just how much time is in between day 1 of official season to week 1 game. With Scrimmage/Jamboree 14 days after start of season.
I think everything is a wait and see approach across the state. Next benchmark will be May 1st. Then ............