Once a month in Pokémon Go, Team Rocket in the game has a new scheme that they want to try and steal new Pokémon, turning them into shadow versions. These shadow versions have closed hearts, making them aggressive, obedient and more powerful. Giovanni and the other Team Rock Leaders have unique Shadow Pokémon at their disposal, and the rotations mean that you can acquire new Pokémon every month, some more sought after than others.
However, due to COVID-19, these rotations have stopped. Giovanni and the other Team Rock leaders no longer have monthly rotations where they use different Shadow Pokémon to fight you. Giovanni no longer has a new Legendary Pokémon at his disposal. The last one available to him was Entei.
You don't expect to see any new Pokémon caught by Giovanni or his crew in May 2020. You won't see a new rotation until the end of September, and therefore will likely launch in October 2020, confirmed by Niantic who has until then blocked the monthly events.
While stopped, players have the opportunity to work their way through those available to attempt to capture the legendary Pokémon Giovanni has captured over and over again. Giovanni is still only available once a month, so you'll have to wait if you do at least once, though.
When the updates return, you can expect new Legendary Pokémon, new mechanics, and new ways to fight Team Rocket. While things are pending, you can find several Team Rocket grunts that are still attempting to take over PokéStops around the world.
