A large part of what I'm talking about is people jumping on RPing au ra before they were even released ingame and before even the tribes were released. Not simply pre 4.0 content - but people jumping onto rping the characters after simply seeing the concept art/a few screenshots from the fanfest 4 years ago. This was before specific tribe info was given out and thus it's in a similar place as the Viera with people jumping onto making characters with no lore basis other than a few stray lorebook II tidbits. That's where the retconning comes from - not from after they were released/simply pre 4.0. I saw people rping them as of a demonic origin or being dravanian related because there wasn't that specific information released yet to players.
Basically yeah as the person above said, making plans that are overly specific is what's going to lead to retconning. Right now this pretty much means a lot of the assumptions being pulled from other games or even assumptions from stuff that isn't clear but we THINK might happen. I think there are ways around this if people really want to do the rp now but I also think that avoiding these assumptions of what the lore is going to be is really necessary for that.