As someone who loves this show dearly . . . I really think it needs to end. Personally, I’d have been fine if it did at Rebellion, but I do believe the story’s run its course. The main thing keeping it interesting to me is that it’s still an (albeit old) Urobuchi script, but since he’s still busy with his puppet show last I heard, I doubt we’ll get any more writing from him. Unless he somehow wrote two scripts back in 2014, which seems unlikely.
All this is to say that if there’s more, I’ll still watch it. I survived Magireco so I might as well go down with the franchise ship. And if Kajiura’s still got that specific Madoka spark that got me into her work to begin with, then all the better.