That’s typical in our area and just beat practice. My cousin tells all his customers the same but if they don’t do it he says ur problem if anything happens. But even 3 weeks doesn’t help in some cases where there is a lot of humidity. The ac brings down that humidity but only so much.We had a similar issue when we installed hardwood floors in our old house. The flooring had to be in our “conditioned” space for 3 weeks before it could be installed so the flooring could get acclimated to the space. We were told that this would prevent cupping and/or warping after installation. This was for solid wood flooring.