If you think the majority of this site is only concerned with roster sharing and 5 man celebrations than you have not been paying attention. Gameplay is and always will be a priority for most around here. The roster sharing is big because it does have an effect on the gameplay. Guys who do painstaking work on things like the "Revamped Rosters" create better player separation and realistic ratings that in turn make the game play better. Not sure if you have ever had the pleasure of using the revamped rosters but if you did you would know what I mean.
The celebration thing is being talked about because, as another poster mentioned, it's in response to the trailer. EA touted all new celebrations and if what we saw is it, all they did was put a new color lipstick on it. Not only is a three man celebration lame it's even worse watching the other two teammates skate away as if nothing just happened is unacceptable.
We all know gameplay comes first but the celebration thing detracts from the NHL experience. No roster sharing, lame celebrations, and the same goalie masks since 2010 with outdated gear seems lazy and unacceptable.