Back in early December on the Mega Man 30th Anniversary stream, Capcom announced that all eight numbered titles in the Mega Man X series would be released on the Xbox One, PlayStation 4, Nintendo Switch, and PC in 2018. However, the actual form these releases would take was never revealed.
After speculation over whether they'd be released individually, as one big collection, or broken up in some other fashion, we may just have our first clue, thanks to the Australian Classification board:
According to their website, the games will somehow be divided up into two packages, designated as "Mega Man X Legacy Collection" and "Mega Man X Legacy Collection 2," respectively. Of course, how they'll be divided remains another matter, whether it's straight down the middle, all the Super Nintendo Entertainment System and PlayStation titles in one and PlayStation 2 titles in the other, or some other way.
Of further interest might be that the two collections have also managed to earn different ratings, as seen above, with something about the earlier games across the two collections somehow garnering a harsher assessment of their content.
Source: Nintendo Everything