There was a time when Marvel went out of their way to give characters a link to mutants. The X-Men were just that popular.
Then, the MCU happened.
Then, the split between Marvel Studios and Marvel Entertainment happened.
The X-Men and the entire mutant sphere of the comics got neglected and shoved aside for a good long while. It's finally starting to come around again, but I doubt Marvel will ever be as eager to throw in mutant links as they once did.