Pokémon Masters EX will introduce the new Monthly BP Challenge in the upcoming Ver. 2.73.0 update scheduled for late September, replacing the current Battle Point reward system with monthly progress that resets each month and allows players to earn new Sync Pairs, dedicated power-up items and other rewards. The update will also adjust Battle Point earnings from Daily Missions, Region Rotation, Champion Stadium and events, while any unclaimed rewards from the previous system will be automatically collected after updating. Battle Points will reset when Ver. 2.73.0 launches, with subsequent points counting toward the Monthly BP Challenge. The update will also remove Battle Villa and its associated Missions, making its currently available Medals unobtainable after the change, while previously earned Medals will remain available. Main Story (Hard) will likewise be removed, with players encouraged to clear both Battle Villa content and the Hard Main Story before the update because rewards for uncleared battles will not be distributed. Pokémon Masters EX is available as a free-to-start game on iOS and Android, with the exact Ver. 2.73.0 release timing to be announced separately.
Source: Official Pokémon Masters EX site
Nintendo & Pokémon Blog 