On August 14th, 2019, the official Pokemon Masters Twitter account for JP announced that the game has globally received over 5 million pre-registrations!
No in-game rewards or announcements were tied to this milestone.
Pokemon Masters doesn't have a release date yet but it has been confirmed to be coming out this summer. The game is currently available in a limited form for players located in Singapore or Canada. Game progress from the limited game has been confirmed to carry over to the official release.
Players who use a VPN are able to access the game from outside of the currently released countries. Check out the guide below on how to get it done.