This. Plus even in the Original series, there are a number of mysteries that haven't been fully answered, and of course, their plot points, as a whole, have been dropped by the X series' timeframe.
Take, for example, all of the "alien robot" shenanigans that have been a part of series since MM3 introduced Shadow Man. Shadow Man was explicitly stated to be an extraterrestrial robot from an ancient civilization that Wily found and modified. And it seemed like they were continuously building on this point, thanks the Stardroids, Sunstar, Ra Moon, Duo and the "Evil Robot". But since 8 (or Power Fighters, if you will), the "robots from outer space" angle hasn't been explored in-game, since. Even though the setup for the crew to meet up with Duo again "someday" is there.
It's the kind of thing that made me wonder if consciously making an attempt to link the Original and X series was really worth it, in the end. Cute references aside, it looks safe to presume that the Original series is just fine continuing onward without really going out of its way to setup for X. Likewise, I feel as if the opportunity for whatever "big ****ing deal reveal" they were planning for the X/Zero series has long since set sail, and it's not as if anybody/anything else from 20XX is relevant to 21XX+.
At this point, I wouldn't at all be surprised if, by the time Capcom is seriously ready to launch MM again, anything pertaining to the previous "expanded universe" timeline(s)/lore is expunged in order to give the brand a clean slate, and you wouldn't need to have read Zan's in-depth write ups to get an idea on what's going on.