When A-listers request for a role, producers listen. Channing Tatum has already discussed the role of Gambit with the X-Men Producer. The only question is when he will appear.

Channing Tatum talked with MTV and confirmed that he has actually met with the X-Men producer:

"I met with Lauren Shuler Donner. And I would love it. Gambit is really the only X-Man I've ever loved. I mean I've loved them all, they're all great, but I guess from being down south - my dad's from Louisiana, I'm from Mississippi, Alabama, Florida - I don't know. I just related to him. He's just kind of suave... He's the most un X-Men X-Man that's ever been in X-Men. Other than maybe Wolverine, who's like the anti-hero. He's a thief. He's not even a hero. He's kind of walking the line of grey. He loves women and drinking and smoking and stuff so he's just a cool guy who happens to have a moral center. I hope it [comes together]. You never know it's a weird industry. If the stars align, I would die to play it. I'm already working on the accent. It's crappy at the moment."

You just can't beat a guy who works on the accent. But not too many fanboys are convinced that Tatum is more than just a beefcake-there are even issues about his body structure! From Screenrant:  "..fans were mixed about whether or not the actor could actually deliver a satisfying version of the character - with many skeptics pointing to Tatum's extremely buff physique as a drawback."

That concern is rather superficial as Fox got away with a tall Wolverine (according to Marvel Universe, Logan is only 5'3") and the more pressing concern is whether he will have a solo movie or be part of the X-Men.

Lauren Shuler-Donner has teased a lot of possible Spin-offs like Deadpool and Mystique (for Jennifer Lawrence). But the only 'real' movies on the timeline is "X-Men: Apocalypse" and the third Wolverine movie as far as the mutants are concerned. There is also the Fantastic Four Reboot in 2015.

It would be easier to write Gambit into Apocalypse rather than build an entire movie from scratch.