tl;dr: The Mega got DMCA'd, which shouldn't be a thing since it's all proxys, but GW sues firsts and asks if it's legal later, and file hosts capitulate first and ask if it's legal never, so it's dead for a while. And yeah they're making a new one, since the guy who runs the mega has to run it on a paid Mega account -- and mega probably doesn't want to do business with him anymore -- so there's that.
I guess it was Commissar Gamza that did it? I don't see a video of him linking the mega directly in the right timeframe, but people in the discord are talking about his stupid "Spacemace 69" thing.