Ideas/theories for what will be the big mcu theme for phases 4-6

I think its somewhat probable that the mcu will introduce a new theme for the movies beyond phase 3(Feige has said they may stop using the phase moniker beyond 3). More so due to Feige also saying they had movies planned out up to 2028. James Gunn also has said that GotG3 will plant seeds which will carry on in the mcu for many years afterward. So what ideas do viners have for what could be the overarching theme/storyline/villain for mcu movies released from 2020 and beyond? I am thinking Capt Marvel's movies will be used to a large degree to work in new story elements and wouldn't be surprised to see a new GotG team take over after the third movie(which Gunn has also alluded to in interviews). For all we know Feige may already have a plan in place to get all the Fox properties minus X-men back by then and work them into the master mcu plan. Some possible ideas:

• An Annihilation story arc which could lead into Conquest(with the return of Ultron)
• A Time runs out style storyline(if they could get FF back)
• GotG3 leading into a Magus/Thanos Imperative/Cancerverse storyline

Probably Skrulls ?

I want Thanos to return as well. 2 movies are not enough for me. I mean , not after all that buildup

Could be a story arc surrounding the glory that is caps infinity war beard.

I'm not really sold on Skrulls being more than something we see in the first Capt Marvel movie. I think that may lead us into something else though.

Not specifically about phase 4 but I don't know where else to put it because I find myself thinking about Coulson, and his resurrection via Kree blood by Fury... and how we're now finding out that Fury is gonna be way more involved and knowledgeable with/on the Kree and Skrulls in particular than we thought. It feels a little bit too neat to be coincidence.

Calling it now: Coulson will be in Captain Marvel.