Interesting question.
Small and X rated events will recover quite quickly and you could argue they have already.
From my perspective as a UK rider and organiser of events in Scotland I believe that the trend re controls will continue away from traditional village hall TLC to commercial premises and as a result we’ll see calendar events and DIYs becoming more similar in future. It’s conceivable then that there will be far fewer calendar events especially at 200km and maybe even we will see a future where only a limited number of “classics” will remain on the calendar.
Thinking over the Scottish rides I've done, they're almost all arguably X-Rated.
The only full controls I can think of I've encountered are Dunblane (once I'd prayed and found it) on the Auld Alliance and Braemar on the most recent running of the Snow Roads.
Other than that it's been the hub nature of the Galashiels 600 and finding Dick or George stamping cards in a café; and a couple of car based checkpoints where it was needed to make the route work.
The Northumbric events are much the same, couple of controls based at campervan or car park, the only sizeable control out on the road was the Colvend sleep stop on the TBAG 600
The only (and therefore also most Northerly) full service event I've done was Deano's Great North Road.
Yorkshire via Essex was IIRC X rated but had both a cafe and pub control on it (due I think to sharing day and inverse of route with the Flatlands), and that was proper south.
Maybe it's just the Southern softies expecting TLC at controls that will end...