In the last year or so there have been a lot of hot takes on how super hero movies cannot sustain the output they have been having onto pop culture with the heavy release schedules from Marvel and DC. The last few super hero movies have shown that they are a broader genre than just guy in tights fights baddies and Deadpool shows itself to be just another wrinkle to expand the field and make it fresh all over again and run all over the box office records for R rated movies.
This has been the case for a few of the last MCU marvel movies as well as the new run of X-Men movies. Winter Soldier and Ant-Man are a '70's style spy movie and a heist movie and the X-Men movies are alternate history period pieces straying from the seeming formula of super hero flms. These movies found themselves into other genres to give another look at heroes but Deadpool carves it's own niche. It's something like a camp movie because the protagonist breaks the fourth wall and makes topical quips, but it's not camp-y. It's violent and crude and just off of reality, kind of like Kung Fu Hustle. It's a bit of a fantasy.
I'm not quite sure where to fit this into my MCU+ because it is such a fantasy. Deadpool gets his powers while dying and going through treatments but he sure looks far down the road of hitting the dead pool jackpot. One theory that can be held for the MCU+ is that Deadpool never really achieved any powers and is dying of his whole body cancer. He is actually hallucinating his own superpowers and fights with Francis, as well as the X-Men he meets, the X-Men in general and the whole Avengers MCU side of things too, for the fun of it. Everything in Marvel is a dream of his and that is why he is able to talk to the viewer and comment on other areas of the marvel universe and the actors that play them... with this in mind, he also mentions Ryan Reynolds' involvement in the Green Latern movie so perhaps that means all of DC's universes (or at least one) are the figment of Wade Wilson's imagination. SO, using this odd theory Deadpool could be first before Captain America: The First Aveger. However, that takes a little of the fun out of the whole MCU+ process so I think I'll keep it right after Ant-Man and before... Big Hero 6 which will be far in the future of the Marvel Cinematic Universe (plus).
I like that this film doesn't go so big of a scale as to destroy a city, just disrupt a high way and crash a salvaged aircraft carrier. I think one way to interpret that aircraft carrier would be to have that aircraft carrier really be a hovercarrier from SHIELD and the Avengers/ Captain America movies. This could be the salvaged wreckage of one of the three crashed hovercarriers from the Winter Soldier (crossing over from Disney to Fox much like the wreckage of the first Avengers being reconstructed in Amazing Spider-Man from Disney to Sony). I like that this is a super hero movie, like Ant-Man, that gives us an engaging story with stakes (in the end the stakes are just for Wade Wilson's mangled face and not really about torture, his girl, or taking his life away from him) that doesn't require massive collateral damage and could be construed as minor news events that take up a new cycle if that. I like when super hero events are big but they don't all have to be Earth shattering Man of Steel events.