According to evolutionary theory, there would have to be a survival value involved in the absence of wisdom teeth in order for their presence to be diminished in subsequent generations.
I don’t think anyone can really justify that NOT having wisdom teeth during the period of time required for several generations to live and reproduce was a survival issue,
or, conversely, that having wisdom teeth caused people to die before they could reproduce.
My mother's wisdom teeth grew roots around her jawbone so that she couldn't open her mouth enough to eat. In a low-tech environment, she'd have died before reproducing. Of course, in the "state of nature," she probably would have had children in her mid-teens (which was before the teeth problem) rather than late 20s.
Not arguing but wouldn’t having the wisdom teeth nourish the woman who nourished the babies? In older times, it was typical for a woman to lose one to two teeth per pregnancy. If she started having children in her mid teens (for an example) wouldn’t the addition of four back teeth (to chew rougher food) help maintain the possibility of having more children?