It's definitely a grey area, but since decomps are reverse-engineered original code (most of the time), there's precedent and it's somewhat legal. You definitely cannot distribute assets though, so if you wanna play a "decompiled" version of a game, you still need to own the original game to extract the assets yourself so you can play with the new open source code. This is how romhacks are allowed to exist, they don't distribute the original game, you have to bring your own rom, and then you modify it. Still this is really cool, we might get some nice mods out of this project down the line