SCP is the opposite of say, the Star Wars franchise where George Lucas (now Disney) gets to say what's canon even if all the fans disagree. In the SCP-verse, everything is licensed Creative Commons (I think), so your own headcanon is equally valid as anyone else's, and fanfic doesn't exist because it's all fanfic.

That also means it's popular to make live action movies like this (https://www.youtube.com/watch?v=xVx2jyDPinw)

I don't see a question in the parent's comment?

Nothing in particular on the 055 page isn't canonical. But any other page on the wiki might contradict anything on any other page. For instance, there are a number of other SCPs and articles that provide conflicting explanations of SCP-055.

> What isn't canonical?

Yes.