Whether to stick to canon down to the last letter or to totally ditch the existence of such lore, like
@Altered Tundra had said, it greatly depends on which route the GM and players choose to take. I feel that most people wouldn't want to follow the canon like a law book nor completely ignoring the lore that is laid right in front of them, which means we will have to try to find a balance of both that best suits the goal of the RP is heading for.
If we choose to stick with canon word for word, most of us would feel suffocated and stressed over spending too much time to extra researches; it may giving rise to unnecessary debates among players on which is the "correct" lore. On the other hand, being overly slack would introduce too much chaotic elements that would also cause unwanted squabbles between the members over uncertainties.
To use crude analogy, imagine a fandom RP like building a house: the canon info acts like the base pillars, the main support frame of the structure, while "original" elements supplied by both GMs and players alike - the what-ifs that gave birth to the fandom RP idea - are the remaining parts that will build up this house. With strong foundation from the basic canon stuff and constructive contributions from members, chances of completing this house would be much higher; otherwise, it will collapse easily, like those numerous RPs that simply die off on a bad note.
I'm currently running a fandom RP with hopes to break (or at least, stretch the limits of) this barrier: it's fandom, the canon stuffs are there, but players are challenged to deconstruct and rebuild the canon, creating complex and surrealistic "miniworlds" set within the omniverse (a generic base) provided by the GMs. Somewhat similar to the Tim Burton's example, but way more intense. ;)