I don't really see how. We had the 11th best PP%, and scored the 7th most PPG last year with 4 Defenders in the top 50 for PP points among D. In Buffs last two full years(2017-2018/2018-2019) Dumba and Spurgeon both had more goals, Suter had just as many points.
Buff had an unreal amount of second assists based on being on that insane Laine, Wheeler and Scheifele PP, but most indications are that it was Laine and Scheifele receiving passes from Wheeler that made that unit tick. Buff just happened to be manning the point on the pass arounds, and only 12 of his 38 PP points were Primary points while Wheeler had 58, Laine 44 and Scheifele 28.
Suter had 17 Primary points, Spurgeon 13, Dumba 18.
He probably doesn't give us an appreciably better PP, because we've already got three defenders that are quite good at (and that's not even counting Hunt who would hopefully not see the ice with Buff on the team).