My dates list is actually missing a date... and a movie.
the list should read
Guardians of the Galaxy - August 1st, 2014
Avengers: Age of Ultron - May 1st, 2015
Ant-Man - July 17th, 2015
Captain America 3 - May 6th, 2016
(Doctor Strange) - July 8th, 2016
(? ? ?) - May 5th, 2017
(Thor 3) - July 26th, 2017
(Black Panther) - November 3rd, 2017
(? ? ?) - May 4th, 2018
(Guardians of the Galaxy 2) - July 6th, 2018
(Ms./Capt. Marvel) - November 2nd, 2018
(Avengers 3) - May 3rd, 2019
So I have to adjust my predictions for the movies....
Maybe Avengers 3 happens on May 4th, 2018 and everything after that is Phase 4?
new predictions:
Avengers: Age of Ultron - May 1st, 2015
Ant-Man - July 17th, 2015
Captain America 3 - May 6th, 2016
(Doctor Strange) - July 8th, 2016
(Thor 3) - May 5th, 2017
(Guardians of the Galaxy 2) - July 26th, 2017
(Iron Man 4) - November 3rd, 2017
(Avengers 3) - May 4th, 2018
(Ms./Capt. Marvel) - July 6th, 2018
(Indestructible Hulk) - November 2nd, 2018
(Black Panther) - May 3rd, 2019
~or~
Guardians of the Galaxy - August 1st, 2014
Avengers: Age of Ultron - May 1st, 2015
Ant-Man - July 17th, 2015
Captain America 3 - May 6th, 2016
(Doctor Strange) - July 8th, 2016
(Inhumans) - May 5th, 2017
(Thor 3) - July 26th, 2017
(Black Panther) - November 3rd, 2017
(Indestructible Hulk) - May 4th, 2018
(Guardians of the Galaxy 2) - July 6th, 2018
(Ms./Capt. Marvel) - November 2nd, 2018
(Avengers 3) - May 3rd, 2019
I'm not too confident in those shuffles, but I had to mix things up a bit. 2 extra dates kind a throw me for a loop. Crazy times for Marvel and comic fans (assuming DC's rumored schedule was legit too).
edit: OP updated with list of confirmed dates from Marvel.