I decided to have a look, here's what I got (unless I messed up the math, which I don't think I did).
Matthews career goals per game:
Regular season .6
Playoffs .44
Yup, story checks out.
I hear so much talk about how Matthews and Marner are the greatest Leafs of all-time, and I call BS. Maybe one day they'll get there, but they're not there yet. The Stanley cup is the goal and if your level of production takes a big dip in the playoffs, IMHO it's completely fair to wonder how great you truly are. Regular season superstars who can't shoot straight in the playoffs - that's the book on these guys as of right now, there's still time to change the narrative but after 7 playoff seasons, it's high time they got started.