Unfortunate, but expected.
Although both 'Deadpool' and 'Deadpool 2' were commercially successful and gained a huge following, there's been little to suggest that a third movie is on the way.
As you probably know, Disney acquired Fox which previously had control over the character, leading many to speculate that the character's fate was doomed due to the fact that Disney typically avoids less accessible and more adult-tinged movies, especially in comic-book adapted movies.
'Deadpool' was one of the most successful R-rated movies ever made, but even at that, the possibility of a third 'Deadpool' seems to be fading fast. Even the character's creator, Rob Liefield, thinks that it's time up for the Merc With A Mouth.
In a recent interview with Collider, Liefield admitted that he's made peace with it. "You know what? There may not be another 'Deadpool' , and I'm fine. Because I have to live with the fact that I had two amazing experiences, two movies I'm extremely proud of, I love knowing everybody on those movies."
That said, Liefield seemed to think that a 'Cable' movie with Josh Brolin might be an option, given how the character can be made distinct from Deadpool pretty easily. "Cable should have his own movie series. He can exist independent of Deadpool in a heartbeat. He has for years. If Deadpool’s been in like 330 comics, Cable’s been in about 520," Liefield said, adding that Brolin seemed excited about the possibility of exploring the character further in subsequent sequels.
Right now, nobody's really sure what's happening next with the Marvel Cinematic Universe - especially post-pandemic. 'Black Widow' is still set for release on November 6th, while 'The Eternals' is set for February 2021. It's not yet clear if the industry-wide production shutdown has impacted the release date for 'The Eternals', or for other movies in the Marvel Cinematic Universe.