I wouldn't really call it unheard of recently. A bunch of guys have done it recently in the WHL and throughout the WHL. Since 2000, here's the list of guys who actually broke 45 goals. Shinkaruk in his draft -1 (but 17 year old season), Evander Kane, Nigel Dawes, Nic Petan, and Virtanen. That isn't really the most impressive group of players. Here's a full list.
Eliteprospects.com - All-Time Stats and Leaders from WHL
Throughout the rest of the CHL its fairly common. Tippett scored 44 goals in 60 games, in a league where the scoring is more transferable to the NHL. Nick Suzuki scored 45 in 65 games, Villardi scored at a 40 goal pace, Patrick scored at a 43 goal pace, Hischier scored at a 45 goal pace, Yamamoto scored at a 45 goal pace and so on. So I wouldn't really call it unheard of. Quite a few guys were on pace to do it last year.
I also don't think he was out 6 months. He took part in the NHL Combine in June and did work in the drills. His injury was only a 2 month or so injury, and I'm not aware of him having surgery or anything post draft. To the best of my knowledge, he also took part in your July Developmental camp and participated on ice.