I really like the empowering message and the idea that collective creations actually affords more expression space to individual creators. I think, like you said, that the fact that it's a joke also lightens up the gravity of the creative act, makes it "just playing pretend", not only when accessing to the lore of the work but also when adding to it. It brings an element of play into the creative act, which helps make it more accessible - make people forget that they are "arting" even if they think they're just "memeing".
But also, I'm not sure people are waiting for anyone to give them permission. Sure, there's a lot of focus on individuals with regards to creation; but also, creation is hard. You have to create a lot of small and simple things before you can step up to some more complex and ambitious stuff; and most people see the works they love and want to replicate them - and the discrepancy between their goal and what they're capable of (just yet) creates a daunting inertia that is very hard to overcome. Playful creation helps alleviate that, and gives a drive to make this myriad of simpler things, so that you almost sneak up on yourself: when you want to make more ambitious stuff instead of just playing around, you've played around so much that you are now able to achieve it, and you can keep playing around - which also makes it easier to undertake the more ambitious works.
Collaborative, artistic (unknowingly?) efforts are also rather common actually; Goncharov is very much our present in that sense. I think so much of the memes that are produced and iterated upon can qualify as a form of artistic expression and can help playfully develop a voice and skills; more directly, the Backrooms and the SCPs are sprawling examples of that as well (very similar to Goncharov in their folklore/community effort aspect and maybe more evidently creative). Game modding, fan fictions and romhacks also help a lot - but it's less collective than Goncharov and more directly artistic.
But I think the fact that it's a form of art that is seen as lesser helps with the dedramatization, the idea that, "oh, I can't do something like that, but this, I can do. I'm just creating a mod." And that gives an intermediate step - you don't have to make something big from the ground up, but you're still able to create something very close to your inspirations.
So to me it's less about waiting for a permission (even though, of course, as you said, there is the feeling of illegitimacy that can add to the paralysis), and more about finding a way to get creating that doesn't feel overwhelming and that's accessible to your skillset, while dodging some of the frustration that comes from limiting your ambition and your scope at first. But that's just a (491 words) nitpick.