The door to a Star Trek actor returning to a series is never fully closed. There are always options and workarounds to bring characters, even those long dead, back to the franchise. That's one of the beauties of science fiction.
The third season of Star Trek: Picard did a wonderful job bringing back characters from twenty plus years past, including Data who had died. The season was so successful, proving that fans wanted more of these characters they'd loved since 1987. And that's why there is such a calling for Star Trek: Legacy, a new series that focuses on Captain Seven of Nine [Jeri Ryan] and would bring back legacy characters even if not on a regular basis.
Gates McFadden is more than willing to return as Dr. Beverly Crusher as she told TrekCentral in a recent interview. Though she had a wonderful arc on Picard, there was much left to be explored about her character and her interactions with her sons. Of course, we didn't get to see a Wil Wheaton/McFadden reunion on Picard, but Star Trek: Prodigy gave us that briefly in season two.
What McFadden is most interested in is the aspect of being a single parent to her children. As she said in the interview, "And I still feel that the character was not… we never saw enough of how she actually deals with her sons. How you actually have to mentor your sons.She was a single parent and I know from single parents that they really are involved in the major decisions that someone goes through in their lives."
Once Wheaton left Star Trek: The Next Generation, we didn't get another interaction between mother and son until Prodigy, and even that was short-lived. But, to be honest, there wasn't much mother/son bonding going on onboard the Enterprise originally. That's something that could be fixed with some one-on-one time with Dr. Crusher and her sons.
Picard proved that Dr. Crusher had changed into a more vibrant, take-charge, and capable character, but it didn't give us those heartwarming moments or even the challenges between a mother and her son. A Star Trek series, whether it's one now or coming in the future, needs to fix this. Not only do we need to see Dr. Crusher and her two sons together, we need a Wesley/Jack meeting that's face-to-face. Just one of the many reasons why Star Trek: Legacy is so needed in the franchise.