Brick Fanatics was able to check out the new LEGO City sets during London Toy Fair, but were not permitted to take photographs. Now that the sets have been shared in Germany, the names at least can be published.
The first sub-theme for LEGO City in summer 2020 is air transport:
60260 Air Race
60261 Central Airport
The second is underwater exploration:
Fans will be particularly interested in 60266 Ocean Exploration Ship, which is a fairly large vessel and features a gap in the middle, so that subs can be lowered from the ship into the water.
60268 Advent Calendar, which will be released on September 1, will be inspired the City Adventures animated series.