Yes, they might have been given a "choice", but it seems likely Kelli would have held it against any vets who took advantage of said choice because that would mean the DCC wasn't the most important thing in their life, the thing that must be absolutely priority over health, personal safety, jobs, and everything else. We've seen Kelli get after girls who have full-time jobs to pay the bills because they don't have a spouse, roommates or anyone else to help foot the bills and cut them because they're not dedicating every spare millisecond to the DCC. We've seen Kelli get after girls who have the gall, the sheer NERVE, to get sick or injured (especially during Training Camp when they haven't even made the squad) because it means they weren't 1000% ready to be on the squad and has cut them for it. We've seen Kelli get after girls for the slightest thing out of their control and cut them for it so what's to say that, should Hannah and/or Brennan took advantage of that, they wouldn't have been cut the next year for taking the time off. Many people would have said that they would have deserved to be cut because they weren't dedicated enough to the team (or whatever "excuse" is used) but they're getting roasted now for being entitled, over it, weak, exhausted, whatever. There was more then enough reasons to keep Brennan and Hannah, but it was a no from Kelli for reasons that don't pass the smell test for me.
2020 wasn't a normal year so Kelli shouldn't even have had a Training Camp. There was no evidence that they were even following approved guidelines in any sense of the word and only doing the bare minimum for appearances. She should have kept veterans only, but that wouldn't get her (Kelli's) face on television nor would it put people's eyes on the DCC. Too bad the Cowboys had such a bad season that even the fans who attended looked bored and like they were only doing it to get out of the house/away from the family and not because they were actually interested in the game/the team/the cheerleaders (plus all the photoshopping of masks onto the fan's faces when they obviously weren't wearing them in pictures).
I like this idea and wish that Kelli had gone this route, but then it wouldn't mean television appearances or any other benefits from having a television show and Kelli seems to have a hard time giving any of those benefits up.