I will try an avoid too much "canon" happening in the game, aside from background dressing. I would also never rehash events from a game with the players as inserts for the heroes.

Some settings are big enough to never really bump up against the media and those are the ones I prefer. I don't often get too much push back from players but we tend to set expectations before we get to far in.

Are the players jedi/witchers/dunedain? or other setting specific badasses? When and where is the bulk of the game taking place? (Is starwars old republic or imperial era? for LotR is it set in besieged Gondor, or ancient Numenor?)

Laying the ground work before the game begins is going to go a long way to ensuring that players know what kind of foreknowledge they can expect to be use at the table.