Deadpool has set multiple number of box office records in just 10 days of its release. By now, everyone who has watched Deadpool must be wondering on whose timeline does it fall - Stewart's original X-Men triology or McAvoy's First Class Universe.
When Colossus says," Let us go talk to the professor. " . Deadpool replies " McAvoy or Stewart? These timelines are so confusing! ".
In Wolverine Origins, we did see "The Merc without a Mouth" Deadpool, if anyone remembered that.
After Days of Future Past altered the X-Men Universe timeline, Deadpool might be a little confused but the timelines are pretty clear. In Wolverine Origins, we saw a rather different origin of Deadpool which was ultimately disappointing and hated by the fans. Thanks to Wolverine changing the timeline in Days of Future Past, Wolverine Origins never happened.
This new version of Deadpool clearly belongs in McAvoy's timeline [Sorry, Stewart!]. We could expect James McAvoy's Professor X reading the mind of Ryan Reynold's Deadpool. But, I guess we just have to wait until Deadpool has a crossover with X-Men, if the studio can afford other X-Men.