"We have actors who really want to play those characters, um, who are - who are very interested in returning, uh, to play them, even if the spinoff doesn't get picked up."
This has been a problem across all the shows in my opinion. Sometimes when a story (or show) is done a character is done too. Not everyone needs a spinoff. Not everyone needs to join Legends just because it was an ensemble mixed from multiple shows. It seems like the producers/writers are influenced too much by the person behind the character rather than what makes sense for a story (Laurel on Arrow, Nate's dad on Legends, Caitlin on Flash, etc)