I've always found this stuff crazy, imagine if Sony came out with exact dates for their lineup of first party games for the next 4 years. Absolute insanity. Do these things ever get delayed?
Yep, Phase 3 used to have an Inhumans movie, and Thor was a summer movie. Spider-Man came in and upset the order, then they killed the Inhumans off and snuck in Ant-Man and the Wasp.
I'm thinking:
May 1, 2020 - Guardians of the Galaxy Vol. 3
July 31, 2020 - Black Widow
November 6, 2020 - Doctor Strange 2
February 12, 2021 - Black Panther 2
May 7, 2021 - Thor 4 (Assuming he's still alive)
November 5, 2021 - The Eternals
February 18, 2022 - Captain Marvel 2
May 6, 2022 - Spider-Man 3
July 29, 2022 - Ant-Man 3
Other Possibilities - Fantastic Four may show up in another movie and then get their own, same with the X-Men, Ms. Marvel appears first in Captain Marvel 2 and then she gets her own movie in 2023. Thor gets another one if he survives, honestly I would bet that he doesn't though. I'd also bet on going to 4 movies a year, big ones in spring, May, and November, and then a smaller Ant-Man sized one in July that will be fine doing about 500 mil.