>.> I rewrote a solid 100 years of history for my Avatar roleplay, changing its entire geo-political background while keeping certain select themes. You can use the wiki, but I had to format a lot of information to be applicable. There's also another thought. A wikia isn't a bible of Lore. If you actually look at a Wikia, most pages are fairly short and wrote by fans; it's the central characters that have the most substantial length. If you remove them, chances are, you don't actually have a whole lot in terms of core information. Additionally, a lot of it is plot-based references. Again, this are often irrelevant or only needed for minor citation if you're doing an AU. A continued universe, however (common in Star Wars, Naruto, etc) would find those more useful.

I do like to have available information, though. I've recently became part of a One Piece RP. I haven't followed One Piece since like episode 35, but I was able to do amplitudes of research to create depth, understand the universe, etc. Something to bitch about, I'd say, is either a) a lack of needed information or b) a GM and/or other person responsible for providing information that won't. Fact is, to create anything in depth, you have to have a source. The more your source provides or can provide, the better quality things will be. Even when writing a research paper, not all your quotes, citations and sources will make it into your paper, but likely many of them will have been part of the rough draft, initial writing process or merely brainstorming. The more information and input available, the more you have to work with. Simple. Even if it doesn't make the final cut.