I'm not completely convinced - to my eye numbers seem to be settling or even rising a little over the past few days (looking at the NHS data - although obviously ignoring the last 3 days as data for them will be very incomplete) and the ZOE case tracking. If they are not still falling currently, I can't help feeling we are likely to see a noticeable rise in a few weeks time when we have relaxed conditions further.
And rise from the VE day was likely to be small anyway - if only 0.25% of people had covid at the time (which ONS figures estimate), and lets say half of them know they are ill so don't go to parties, or at least keep well away from other people if they do. That is 82500 people who are infected and are asymptomatic. Lets say, of the, 20% got really pissed and didn't social distance - that is 16500 asymptomatic but infectious people hugging other drunk partygoers. Now lets pretend they passed the virus on to 3 people in an orgy of slobbery kisses and hugs. Or something. So that is potentially 50,000 new cases. However I would guess that people getting drunk at VE day celebrations and forgetting to social distance are going to tend to be in the younger adult age groups, so probably less than 10% or the will make their way to hospital, and lets overestimate and say 0.5% of them might die. That is 250 deaths. Which will be spread out over the next 2 weeks. And thus will be barely noticable.
What is more of a concern is the 25000 who contracted CV at the VE celebrations and have no symptoms, so take it to work, school, etc and pass it on again. Which is where the potential for flare ups over a single day lie - but it doesn't show as a single large spike, more as a creeping increase...
That said, and despite my concern that talking about the virus "exhausting itself" is wishful thinking, hopefully the track in trace will be in place quickly enough that any further increases in the number of cases can be carefully managed.