I don't know why you are so insistent on fighting back on this. Do you have info to say he's a different height?
What if Zdeno Chara shrunk to 6'1? Would that change the calculus of his height? It would, but until we have reason to believe he has shrunk, why should we operate in hypotheticals? It's not as if there's much reason to believe Rossi's listed height isn't correct. And it's possible for 18 year olds to grow, but most people are done growing by 18. Rossi's nearly 19, as well. Some players in this draft haven't even turned 18.
And you've started moving the goalposts here about Rossi. There's no problem with being a fan of Rossi. You can say you think he'll be the exception at center with his height/skating, but this hypothetical game where you muddy the waters of his height doesn't accomplish much. Yes, anything is possible. It doesn't mean we need to speculate on anything. There's an agreed upon set of facts that you either seem to want to question or not accept. As far as the public knows, there is no recent top 6 center in the NHL shorter than 5'10 (unless you count Tyler Johnson). As far as the public knows, Rossi is 5'9. If you know otherwise to either of those two things that is pretty agreeable, you should alert everyone. Otherwise, this speculation game is worthless and doesn't add to the discussion.