I believe it's possible. Because of 3 reasons.
1. The X-Men universe in itself is big enough to sustain an entire universe by itself. Marvel could make an entire phase dedicated X-Titles if they really wanted to.
2. Kevin Feige is a fan of the X-Men and has expressed over the years how he would love to have them back. THR last year mentioned Feige being very excited to dive into the X-Men universe and MS already discussing a rebooted Wolverine
3. Before 2012, the X-Men dwarfed the Avengers in popularity. And the ONLY reason TA became what they did, was because of Marvel Studios building up their brand and Disney pumping billions of dollars into it. What do you think is going to happen when Marvel Studios gives the mutants the same treatment as the Avengers? When you start X-Men merch, X-Men cartoons, X-Men theme park rides etc? Who's to say they won't take back their crown? Now, yeah, the Singer films have tainted the brand. But the X-Men under Feige could easily prove to be a viable replacement for the Avengers In the future.