Obviously no clear-cut answer possible at the moment, but how would this work if thousands asked to defer, or withdrew in order to apply again next year? Presumably grades will be up (as they will be a)predicted - so often aspirational and b) matching university asked-for grades) so current yr 13s would be applying in the privileged postion of having grades in hand.
On the TSR loads of kids are saying they won't go to university as planned if their experience is going to be crap (eg no social interaction, or if it's online). What if 50% of 2020 starters say they want to go next year instead? Obviously the year 12s would then defer and push on the problem ad infinitum... 