Call of Duty 2020 will be based on the Black Ops franchise and developed by Treyarch Studios, who just released a new Black Ops last year. It was previously Sledgehammer Games turn to make a new COD but Activision has reportedly removed them from the project and put Treyarch in the lead.
Call of Duty 2019 will be revealed at the upcoming E3. It is all but officially confirmed to be a new Modern Warfare. After the new Call of Duty this year, next year will see the return of Black Ops with another new entry but this time there will be a single-player campaign for it, unlike last year.
According to a report by Kotaku, Call of Duty: Black Ops 5 will be primarily developed by Treyarch Studios with Sledgehammer Games and Raven Software taking a supporting role. The single-player campaign will be set during the cold war (possibly Vietnam) and it will also be cross-generation so it might be released for PS5 and Next Xbox along with the PS4 and Xbox One.
Call of Duty: Modern Warfare 4 is the new game set to launch later this year and will be revealed at the upcoming E3. It is currently being developed by Infinity Ward who previously worked on Call of Duty: Infinite Warfare.