PSO2 will launch on PC in North America (although anyone can play it regardless of physical location since it’s not region locked) “late May” 2020.
The North American release includes the first three years of game content from the Japanese release, though it incorporates a lot of quality-of-life and balance improvements. Sega has said there are fun-filled “events, collaborations, and expansions” coming down the pipe, so expect the subsequent eight years of Japanese content to show up on this port down the line. Phantasy Star Online 2 was originally released in 2012, and has had longevity in Asian regions, but never made its way to the West.
The good news is that cross-play between Xbox One and PC players will be enabled the moment it goes live on the Microsoft Store.