He definitely looks like he's grown, he started the year listed 5'7 150, but it looks like he's closer 5'8+ 160 right now.
I would expect him to end up listed around 5'8.5-5'9 160-165 by the time the combine rolls around. He just turned 17, lots of potential for growth.
Regardless, with the success of guys like Kane, Gaudreau, Hughes, Hughes, Bedard, Fox, Point, Caufield, Debrincat, Keller, Bratt, Cooley, Maccelli, Atkinson, Jarvis, Garland etc I think GM's should take any size concerns about a guy with Mooney's skating ability with a grain of salt. And yeah, I know some of those guys are "5'10", I think that's probably generous.
If you can skate and think fast, you can be an impactful NHL player, no matter your size.