For special abilities (from sponsor), my experience is that I received useless SAs (corner kick for a ST or DMC, penalty kick for a DC, etc) for 2-3 seasons in a row, then useful ones (shadow striker for AMC AMR/L, free kick for AMC/ST etc). It kind of alternates between useful and useless ones in this manner.
As for playstyles, I don’t have much info about it as I haven’t got it that frequently, but I expect similar pattern if you consistently “buy” random playtyle coaches. And this season’s random midfielder gave my MC/DMC box-to-box.