Depending 100% on who the RW is on that line. If Bruins sign Kovi or re-sign Nash and Pasta stays there... I think he can threaten.
I think people just fail to realize that most of Marchand's points spike has been (1) the 20-25 point spike in PP he has had because Julien gave him ZERO PP time and (2) Pastrnak is easily the best RW that line has had (including Seguin).
The extra PP points are not going away, but the 5 on 5 additions are reliant on Pasta sticking around.
edit: in his first 6 seasons, Marchand averaged under 3 points in PP time per season. The last two? 24 and 23.