You can't just "cancel" a multi billion euros event like that.

Their will be no riot because the places where the games happen are closed to rioters. And even if their are some further, it will be handle correctly this time (while usually it's purposefully poorly handled in order to turn the opinion against the movement...) you can be sure lol, and will not impact the event IMO

Anyway it will not be just canceled, it's strictly impossible