I might be in the minority when I say I actually enjoyed all three seasons of Star Trek: Picard. It wasn't perfect, but the show got gradually better as it progressed, and the reunion of the Star Trek: The Next Generation cast in the show's final run was brilliant. That being said, I enjoyed more than just the fan service. Picard introduced an array of new characters, and may could return to be part of the Star Trek: Legacy cast if the follow-up show happens. Sadly, one of Picard's standout introductions can't really be among that group.
Star Trek: Legacy Can’t Bring Back Cristobal Rios If Picard’s Spinoff Happens
Captain Rios already left the 25th century by heading back in time (& dying there)
Star Trek: Picard's ending takes place deeper into the 25th century than ever before, which means there are further opportunities for the Star Trek timeline to be added to in exciting new ways. Presumably, Star Trek: Legacy would pick up shortly after the Picard finale, which means there is a surprisingly long list of characters introduced specifically for the Picard who would be eligible to return. One of my favorite figures exclusive to Star Trek: Picard was Santiago Cabrera's Cristóbal Rios, but he's essentially gone for good.
Rios was instrumental in Star Trek: Picard seasons 1 and 2, but his exit at the end of the second run was executed in such a way that it wouldn't make sense for him to come back in Star Trek: Legacy. Of course, I'm aware that Star Trek is a sci-fi franchise, but this is one of those instances where I strongly believe trying to fix this decision with a trope-led retcon would be one of the least suitable decisions possible. So, I just have to live with the sad reality that we've probably seen the last of Captain Rios.
Why Rios Was Written Out Of Star Trek: Picard Season 3
The incoming members of the Star Trek: The Next Generation cast were too expensive to also keep Cabrera
Star Trek: Picard season 3 saw the biggest shakeup in the show's history when it came to its casting changes. Unsurprisingly, Patrick Stewart remained in his titular role, but Cabrera was among a group of four key stars dropped ahead of the final season. There's a very simple explanation for this, and it all comes down to the show's incoming cast members. However, they're known better by a different name - the cast of Star Trek: The Next Generation. The show's budget was set to balloon because of the star-studded cast, so Cabrera and the others had to go.
Thankfully, Cabrera was at least given a proper farewell in Star Trek: Picard season 2. It would have annoyed me if he was still among the cast at the end of season 2, only for season 3 to open with an explanation of where Rios had gone. He deserved an onscreen exit, and he got one. Besides, with the landmark plans in place for Star Trek: Picard's final season, I doubt there would have been enough time to give Rios any kind of respectable storyline. It was essentially Star Trek: The Next Generation season 8, making a casting overhaul necessary.
Why Rios Is A Great Star Trek Character Who Deserved More Than His Fate In Picard
Captain Rios could have been explored further in Star Trek: Legacy
Guinan (Whoopi Goldberg) informs Stewart's character in the Star Trek: Picard season 2 finale that Rios died in a bar fight over medical supplies, decades after arriving in 2024.
Rios survived into old age and went out in a blaze of what made him who he was, so it's tough to argue that his departure from the show wasn't actually quite fitting. Then again, I can't help but feel like the character had far more potential than what he was able to fulfill. Star Trek: Legacy would be the perfect kind of project to explore a character like Rios even further, but the end of his arc in Star Trek: Picard has taken that possibility away.