I understand the sentiment, but I don't think Disney is gonna go out if their way to sabotage Deadpool's appeal. I think at the very least, they're gonna get as many folks from the first two movies as they can and tell them to go nuts, and Deadpool 3 will be a very entertaining watch.
But that will effectively be Deadpool's last hurrah, because when it comes to Marvel sequels, Disney is way too fond of homogenising them and watering them down to either closely resemble the first movie or to use it as a crutch for their extended universe.
Ant Man and the Wasp is the worst example of this, and at the risk of sounding like a contrarian shithead, it shows plain as day in Guardians of the Galaxy 2 as well.
Ant Man 1, while not the finest superhero movie ever crafted, was a fine comedic superhero flick with some decent effects. I genuinely believe it got shit on way too hard when it came out. Ant Man and the Wasp looked good, but the dialogue and plot wasn't anywhere as near as good as the first movie was. This movie was overrated as fuck - I liked the cut of the plot's job, but the whole thing was a bland, uninspired mess.
Guardians of the Galaxy was an unexpected breath of fresh air for Marvel. It was a comedy action movie that also served as an ensemble piece with its share of pathos and drama for each of the characters. Ending wasn't too flash, but the movie was very enjoyable.
Guardians 2 had the formula down to a science. Most of the movie's humor was "set-up comment, set-up comment, joke. Set-up comment, set-up comment, joke." In that order, ever-repeating, until the movie ended. When The Last Jedi came out, the constant humor and extravagant CGI setpieces reminded me a lot of Guardians 2 - that's one reason why TLJ didn't measure up to TFA for me, it felt like a cheap Marvel movie. It felt like Disney had crossed the streams way too fucking hard.
I didn't mind Guardians 2, while Ant Man and the Wasp was an actual chore.to sit through from one of Ant Man's greatest defenders. Marvel movies had always been kind of comedic, but Ant Man was a sillier movie than most of them and it was an entertaining watch. Everything Ant Man and the Wasp did felt like a shadow of the original movie, and the super-serious plot with Ghost felt so generic and unwatchable, even though I enjoyed the design of Ghost and the effects of their movement.
Here's the thing. After Disney bought the MCU, they allowed the creative forces in those early movies to thrive and create fairly unabashedly. When that proved to be successful, they worked with the Marvel brains trust to keep that whole brand fresh, entertaining and viable.
Deadpool 3 isn't a Marvel movie, even though it's a Marvel property. They will bring Deadpool and/or his universe into the MCU, even as a glorified cameo machine, but before they whore Deadpool out in the way he's usually whored out in media that contains him, they will work hard to match or exceed the expectations of Deadpool movie fans to build goodwill. Then they'll get commendations for bringing Deadpool into the MCU, even though he's a bland cameo machine who keeps appearing in other movies for a quick meme scene, and he'll burn out into a generic pop-culture list staple extolling his quirky, meta humor, despite any wit or grit that comes from his character being absent for years after Deadpool 3 came and went.