- Purification confirmation and key filters data show that "shadow” Pokemon exist
- Dialogue from each of the team leaders talks about "defeating" an enemy and gaining their Pokemon
On June 8, 2019, Pokemon GO dataminer @Chrales released information discovered regarding a Team Rocket Invasion event happening sometime in the future.
Players can expect to be "purifying" Pokemon from their "shadow" form. Badges associated with purifying Pokemon and defeating Rocket Grunts have also been discovered.
Purified Pokemon will know the exclusive move Return(move stats unconfirmed), be a higher CP and have a lower power-up cost, suggesting they might become Lucky Pokemon.
The team leaders also seem to be taking an active role in the event, directing the player through what can be only assumed to be a Special Research event.
The dataminer also revealed dialogue associated with Team Rocket Grunts themselves.