There is no official confirmation yet, but according to Colin Moriarty, Ratchet & Clank's new adventure is coming soon.
Insomniac has been recurring news in the midst of video games, but largely because of the possible sequel to Marvel's Spider-Man, but it appears that the next game in the stadium is another chapter in the Ratchet & Clank saga.
"We will receive a Ratchet and Clank between them [Spider-Man 2018 and its sequel] on PlayStation 5. I feel that it will be a launch game, since it has been in development for a long time," said the former IGN editor in a recent episode of the Sacred Symbols + podcast: Episode XXVI: The Waiting Game.
Remember that Insomniac Games was bought by Sony after the success of Marvel's Spider-Man, so it is possible that there is some internal pressure for the development of a game that can reach the market with the new PlayStation 5.
The last title of the saga was released four years ago and is available in the PlayStation Hits catalog.