>>108747323Mega Man was popular a long time ago, its star faded with the shift to 3D but then it returned as people had nostalgia for the originals, then faded again. Then perhaps people with nostalgia for that resurgence period growing up there is more of that again? Mega Man has some great games after all.
Re-releases in more easily accessible formats have likely helped it as well with the PC and virtual console access to it.