I didn't grew an inch in height after I was 16. But went from 150 to 200 between 16 and 21.
Regarding goals, sorry, I will not play. This is exactly the type if meaningless talk I have no time for. It is a fact that they played a BCHL level goalie. And all the hype of the "historical" season relies on points scored against horrible team with no goals, no meaning and goalie that should not play on this level
At the end of the day in 25 games against normal KHL teams Michkov scored 12 pts.
Maybe it's just a setback and next season he will have Matthewsesque(in NL) performance in KHL. But how can you or anyone else really argue that he had an impressive season?
Remember, he is supposed to be the best after Ovechkin. For Nichushkin/Kravtsov/Podkolzin this performance would have been good, but Michkov is not that, he is special, like what Fjordy said, he is Kovalchuk shot plus Kucherov IQ, a Prodigy, a true next one. How is it impressive that he failed to make SKA, scored 6 pts vs an amateur goalie and had 4 pts in 13 games vs Belarus?
I personally grew 2 inches in height since I was 16 (but also was growing until I was like 21, not until 19), also knew a guy who would grow more than 7 inches after his 17th birthday, but if he would be a hockey player that would be a disaster, as in that case he would have to rebuild his game almost from scratch. Still I think you'd agree that late growth spurts this big happen more like a rare exception, can't think of any kids who played against Michkov that would grow so notably (maybe there are some, just can't remember now).
As for the goals, I don't argue that Zehao Sun isn't really a quality goalie, just what I mean is that it didn't have much effect on Michkov's numbers, their bad defense did though.
The thing is that Kunlun isn't the unexpectedly weak team, the KHL always had ones that would be just a disaster - Sochi, Dinamo Riga, Admiral in previous seasons, Slovan, Vityaz, Medvescak, Minsk, Kuznya, Yugra, Lada and Spartak in the years before - all of the players you have listed played against bad teams too, but somehow so far noone thought of the idea that the points they scored against those shouldn't be counted.
As for impressive, it all comes to the definition - he has one of the best seasons in the KHL for a prospects in the first draft year ever and that's while being physically just maybe borderline ready. Kaprizov was in the same situation too and had 8 points in 31 games - that was not too great, but still impressive. Statistically Tarasenko had the best season, and even if we extract these Kunlun points that still would be in the same ppg region as Michkov, while Tarasenko was on another level of physical readiness. Maybe these guys weren't impressive for you and you have other candidates to compare?
As for SKA they favor athletic high-intensity guys, so no surprise Michkov wasn't suitable for them yet, that's actually a notable question mark how he'll fit there next season. As for the Belarus games, I'd like to remind that at that time he just lost his father, even Ovechkin's performance went down this season after that kind of a loss and he isn't a teenager.