One thing I've been thinking of for over a year now would be some kind of game "covers" jam. Like, take an existing game and redesign it in your style? Still haven't figured out the particulars of explaining exactly what that means, or how to avoid problematic stealing/appropriation of work.
Viewing post in TTRPG Game Jams - Ideas/debrief
That would be interesting, I'd say a lot of games fit the idea of a "cover". PbtA games might count as covers of Apocalypse world (mechanically), Dungeon World might be a cover of D&D (thematically), etc and that's usually not a problem. There would need to be some lines drawn as to what counts as plagiarism, but I feel like for the most part it should be fine?
I really love this idea and I'd definitely join it; I've more than once considered taking games that are in systems I find too complicated and/or find the base game problematic and reworking them into an engine that's a lot lighter and simpler. I agree that Dungeon World is kinda a "cover" for D&D, and Urban Shadows is one for the World of Darkness, and that's the sort of thing I'd be really into.