As it had already been revealed here in the Poké Mundi Pokémon Regice after almost a month in the Raid battles, it would be replaced today (19) at 17 hours by the Registeel. This is Hoenn’s second titan to date the game and can be captured in level 5 battles until 16 August. In addition, it was confirmed that Alolan Exeggutor, Alolan Marowak and Alolan Raichu will also be available in lower level Raid battles.
Source: Pokémothim