If they had let this play out instead of quarantining well people....for a year...these variants would not have time to develop.
The emergence of variants is not a function of time, it is a function of the number of infections.
The likelihood of a viable variant seems to be on the order of one in 50 million cases.
It wouldn’t matter if those cases occurred in 18 weeks or 18 months. You would still wind up with the same number of variants circulating.
You might be able to make the case that the variants would be more likely to remain in country of origin under a laissez faire approach, but that assumes travel restrictions more robust than likely possible given the ineptness of national governments and health agencies.
And the harsh counterpoint to your hypothesis is that there would have been NO VACCINES before the pandemic ran roughshod through the entire population. Add those otherwise vaccinated folks into the case pool and you’re far more likely to see much higher case numbers and therefore more variants under such a scenario.