Star Trek 4 is that ever-fleeting movie that was happening/could be happening/is happening. Though there has been some movement as of late, we don't truly know if the film will ever come to fruition. The cast have moved on, and while they're still interested in returning, life goes on. Zachary Quinto, who played Spock on all three of J.J. Abrams' Kelvin timeline movies, is one of the main members of the cast who would still love to return.
In an interview with Variety, the actor said he was "open to it" and "would love it." Even if it didn't happen right away. Quinto pointed out that the cast of Star Trek: The Original Series starred in movies well into their 50s and 60s so there isn't a set time when the film studio would need to say they're too old. Even Patrick Stewart returned to his character from Star Trek; The Next Generation at the age of eighty. So what Quinto is saying does make sense. Does it really matter if the cast is a little or a lot older when a movie does eventually come to fruition?
"There’s no cutoff. The original cast did movies for decades, well into their 50s, 60s. The stories might be different. We might not be running as fast on the other planets, but I think anything’s possible, and I think there’s nothing more fulfilling as an artist then [sic] to come back to something after time has passed, and cultivate a relationship with it from a completely different perspective, and a completely new point of view."Zachary Quinto
Though fans weren't too thrilled with the direction Picard took, there is still plenty of time for the cast of the Kelvin timeline movies to grace the screen again as most of them haven't even had their fiftieth birthdays yet.
This doesn't mean we want Paramount to continue to drag its feet with the production of Star Trek 4. After all, this is being billed as the final chapter in the Kelvin timeline. And many of us are in our fifties and sixties, and we'd like to see it sooner rather than later.