The point about the surge subsiding has to do with the rate of mutations and the available time for vaccine rollout.

Again you're talking about it as if the rate of vaccine production and rollout doesn't change at all compared to the first time they came out which is just not the case. To go from not producing something at all to producing a modified version of it and to go from not distributing something to distributing a slightly different thing are not the same. Especially with mRNA vaccines, these have never again been mass produced and production as well as distribution is still ramping up globally. If people can receive a new flu vaccine every year, there is no reason why the same and better can't happen with COVID, where there's like 100x the pressure for that. The main concern is countries which can't afford to vaccinate many people. Although at least these countries are on average at least handling it less catastrophically than Europe and the US.

The variants were known and sequenced in December. They announced work on it in January. They are testing now. That is 3 months lag time already and testing isn’t done. This is all in the context of variants against which current mRNA vaccines, like Moderna’s, are still pretty effective.

You're talking as if variants don't have lag time for spreading themselves. Also it was closer to 2 months, the month just started.