There's now a new setting under "privacy" to decide the default active tab in the DM view (fig 1) and we've implemented filtering DMs by "followed only" (fig 2) as the lowest hanging fruit 🍓 .
DMs from people you don't follow are still received and saved - this is just UI filtering for now. And agree with what @j12t was pointing out, followers/following isn' really meaningful for classifying relationships or trust...
1/2