I thought about this, because I thought that this would actually be such a cool stunt to pull for really any show with magic or syfy elements.
I don’t know if any distributor would ever okay something like that though, since finales are such huge events that get really played up for publicity in advance.
the closest i can think of a stunt like that being pulled off is agents of shield, where the first half of the first season is incredibly paint by numbers dogshit on purpose, even though it meant every review trashed it. then there's a massive twist around episode 13 where the hydra situation from winter soldier basically fucks up the entire team and people are revealed to be double agents and it somewhat works.
but of course that was 1. the first season and 2. they were guaranteed a lot of seasons because of the marvel tie-in. So they were allowed to risk the twist not turning out well because they knew they could always retcon or walkback anything audiences didn't like in the next seasons. You're obviously unable to do that with a finale.
and she wishes they'd given her a scene or two so she could get her SAG health insurance for her cancer treatments.
this is probably another big reason we ended up with this huge cast in this last season, you can't act like Joss Whedon anymore and kill off major characters on a whim because everyone understands how much everyone needs SAG. so everyone has to get a bit of screentime every episode, and if you leave off anyone you get pity party articles like this
Prison Break having a random season drop nearly a decade after the show originally ended. I don't think any other TV show has done that, or at least none I watched.
nah fox was doing that a lot. 24 had a new season 4 years after the show ended, it kicked off the "revival" crazy of the 2010s. X-files also did it and prison break was another attempt at it. besides the x-files none of the shows they did a "revival" of worked out. the other channels had a better go of it but thats because they rebooted cheap ass sitcoms instead of huge dramas.
the roseanne reboot technically ended last year, thats how fucking successful the "revival" was, most of the rest of them was a "one and done" and didn't work because the audience that gave a fuck moved on/wasn't enough to keep these shows renewed.
the showrunner for the roseanne reboot even said the main reason theirs worked vs others was because it was more focused on the kids, a sort of next generation type show like you used to see. but obviously they still live at home because they're poor. it was actually a really smart move because gen X really are the only ones still paying for cable, so a show focusing on following those people is more likely to work vs one pandering to boomers (dead) or millenials (cord cutters) and the 24/prison break/x-files really was pandering to millenials whereas the sitcoms were pandering to boomers (do you know anyone under 60 that even remembers murphy brown?)
I'm actually semi-surprised House never got a shot, i guess the main reason that didn't happen is Bryan Singer owns part of the show. but it really feels ripe for a revival.