10 Ways The MCU Can Reboot Deadpool
7. An Iron Man Connection
Having Deadpool's origin connect to Tony Stark (and arguably any of the Avengers) is excessive and wouldn't feel organic, but it's always a possibility that Marvel retcons Deadpool into this universe with a connection to Stark Enterprises, the Battle of New York, etc. We've already seen it with Baron Zemo, Mysterio, and the Maximoff twins.
How many times will the MCU return to that well? We must assume that we haven't explored the last of the mythology of Iron Man and Captain America, especially with the Black Widow movie doing just that. HItching Deadpool's wagon to a previously established character or monumental event aids the "it's all connected" mantra while making it easier for general audiences to bridge the gap into an MCU without marquee characters.
Stark Industries and S.H.I.E.L.D. each had their dark corners. It's not a stretch to assume that they were experimenting on humans like Hydra was. Could an attempt to replicate the Super Solider serum have created Deadpool? Could Loki have tormented Wade Wilson's mind off-screen, driving him utterly insane while also unlocking his powers?
Is it a bit reductive? Absolutely. Will it make hardcore Deadpool fans boycott the MCU? Absolutely not. Altering Mysterio's origin was a little hard to swallow but the MCU made good on it with a fantastic actor, great script, and awesome visuals. They'd do the same in a similar situation with Reynolds and Deadpool.