This seems like a fairly realistic set of assumptions for what to expect on the COVID-19 front next year as vaccinations begin to roll out. Things start to get notably better by ~April but it takes until mid-to-late summer before we approach herd immunity.
https://covid19-projections.com/path-to-herd-immunity/

The one major downside scenario is if vaccines prevent disease but don't do much to curb *infection*. Otherwise though these seem like pretty middle-of-the-road assumptions. I think he may underplay the role of seasonality a bit, which could help in the summer.

The other thing that seems likely is there will be some pretty fierce debates in that interim period from April-July or so about faster or slower paths to reopening.

One last thing to worry about a tiny bit is the chance of a small wave next fall/winter. If things are going well by late summer, it may be harder to persuade people to be vaccinated and people will really let their guard down. But resuming crowded indoor activity could be risky.

That's not to say "we're going to have Zoom Thanksgiving again"—I don't think it will come to that, fortunately. But we need to not lose momentum on encouraging vaccination, especially since immunity acquired through infection may fade for some people at 1+ years out.