The studies compare outcomes of folks with boosters to folks with lower vaccine levels, and the results, to me, seem rather clear.
If some in one group had a prior infection, so would the same number in the other group, perhaps even more so, as the unvaccinated would be more likely to have had a prior infection.
These are pretty large based studies. Anyway, I too am against mandated vaccines except perhaps in small select groups. I would get an update.