I think the expectations on Gaudreau by Flames fans are higher then you suggest. I was attacked in the summer by Flames fans for comparing Gaudreau to Mike Cammalleri.
Flames fans were and are throwing around Kariya, St.Louis, and Kane as the Gaurdeau comps and balking at any comparison to lesser players.
When those 3 are the only comparisons that Flames fans will accept, it paints a pretty clear picture who they think Gaudreau is, and it's a higher level then what most other fans are predicting for him to achieve.
You have received a few responses, but none that have been as straightforward as I was thinking there would be.
You were 'attacked' so to speak (and without looking at your posts or the replies) because it is a poor comparison. You watch Gaudreau play, and it is literally absolutely nothing like Cammy. I am not sure what 'lesser players' you were trying to compare him to, but if you are comparing players strictly by size, well... it would be like Flames' fans comparing McGrattan to Mario Lemieux - obviously an extreme exaggeration to illustrate the point here. You can't look at how a player is built, and directly compare two players.
The reason he has been compared to Kane, Kariya and St. Louis (St. Louis in my opinion is a poor comparison, but Kane and Kariya are fairly good) is due to PLAYSTYLE. It has ZERO to do with expectations. There are people who have compared him to Gretzky - and again, it is PLAYSTYLE. Nobody in their right minds is going to expect Gaudreau to be Gretzky, but the way he sets up behind the net and how he is so elusive does resemble SOME of the Great One's game.
I haven't read one post that was even half-serious saying Gaudreau = Kane, much less anyone else. One of the comparisons that keep popping up is Gerbe. Flames fans aren't taking 'offence' at making a comparison at a 'lesser player' as compared to Kane. If you have compared him to Gerbe and taken flack because of it, it is purely because Gerbe plays a completely different game than Gaudreau, and the comparison is a lazy one based on size only. Again, you simply can't compare a Mario Lemieux to any other player of similar height, can you? It is very plain to see that Gaudreau's playstyle resembles Kane and Kariya more, and if anyone compares his playstyle to Gerbe than they have either never watched Gerbe, or never watched Gaudreau, and are just making a comparison strictly on size which is absolutely meaningless.
Again, just to make sure you understand, "Play Style" =/= "Career Expectations".