Would Back For The Finale count if it's not a finale

Would Back for the Finale count even if the example isn't actually the show's finale? For instance, say they bring back characters for a revival, reboot, or special several years after the show has ended?

The example I'm thinking of is Phineas and Ferb The Movie: Candace Against the Universe, which is a film based on Phineas and Ferb which was made 5 years after the show ended, so it isn't technically a finale, but it does happen to be the last thing made for the series.

Also, going through the page itself, there seems to be a lot of other questionable examples on Back for the Finale, including some examples where characters just show up for the last scene of a stand-alone movie. And certainly a movie that was meant to serve as a stand-alone movie and is thus the first and only installment of it's series can't also be considered the finale of it's series as well, right?

That is a finale. I think you're confusing the more general finale for the more specific Grand Finale. Don't forget that there is also the Astral Finale, Big Rock Ending, Crossover Finale, Distant Finale, Ending Memorial Service, and Fake-Out Fade-Out, to name a few from Ending Tropes.

Link to TRS threads in project mode here.

That depends on a lot of factors. You will want to check Beginning Tropes if it is the start of the story.

Link to TRS threads in project mode here.

The description for Back for the Finale seems to indicate that this trope is specifically about series finales, not just regular endings. It specifically seems to apply to characters who have been absent from the series for a while or who have been written out in someway, only to come back for the very last episode because it's that big a deal. For movies, it doesn't seem to make sense, because if the character was there in the earlier part of the movie, he can't really "come back" for the final scene because he hasn't really left.

It was also my impression that this trope was more about casting than about the actual characters. For shows, getting an actor who has left the series for a while to come back to film the last episode is kind of a big deal. But for films, actors who filmed a scene at the start of the film and also come back to film a scene for the end of the film isn't really a big deal because they could usually just film those two scenes on the same day.

I think maybe there could be a separate trope for examples that apply to general endings and one that applies to actual finales (That is to say, an ending installment of a long-running work).

the closing part, scene, or number in a public performance

Link to TRS threads in project mode here.

There are different types of finales. But the description for this trope seems to reference series finales specifically. So that's what I'm going with.

Series Fauxnale covers the idea that what is going to be the actual final installment is not always clear for everyone involved, so even if a work has a Grand Finale vibe to it with a Back for the Finale example but the work continues on, that would be something to note in the example itself. Scrubs had numerous cameos in the eighth season finale, which was intended to be the Grand Finale, when season nine showed up it was more of a Spin-Off but it doesn't invalidate the effort put into the eighth season finale.

After some thought, it seems like the Candace Against The Universe example is just The Bus Came Back.