So from now it's...
I'm just going to throw things running around in my mind right now.
I personally still find it weird that Cap 3 and Doc Strange is only 2 months apart and that there isn't an August or November release in 2016. Then again they are doing it in 2017 so I guess that's their new route. I want to put Avengers 3 at Jul 27 or Nov 3 of 2017, likely July date with May 5th being Thor 3. Then Nov 2017 kicks off Phase 4?
Then again I have a feeling Marvel might have decided to make the Defenders movie for the big screen instead with a smaller budget so they slotted it as a third film for 2017 and then they can add those guys for A3? Defenders film can be any of those 3 slots but it's kind of difficult to see Avengers being a November film. I think Jul 6, 2018 is pushing it with extra heroes added (Antman, Doc Strange, GotG plus a possible third hero for that movie slot if A3 is in 201
unless they kill off Cap in Cap3. BP is likely the next candidate for a new hero film for Phase 4.
Another possibility is that they are making A3 a two part film to deal the huge Infinity Gauntlets story hence A3: Part I & II would be Jul & Nov of 2017 or make it a year apart with Nov3 2017 & Jul6 2018 therefore the conclusion of the Avengers still in the front of the summer blockbuster time for 2018. Then Phase 4 starts in Nov 2, 2018.
You're move DC!