Oh so it's finally on this site too. Not really much to add to my previous comment.
Wouldn't it be fun to imagine that the student council play they watched (the one with the boat and the stream) was also helping one of the actors to change like it did for Touko? Like the tradition they created keeps helping people get over their drama? lol
Miyako and Sensei kinda didn't get a final scene together, we only saw them separately. But the way Miyako casually talked about her in front of the gang makes me think since they all graduated, the adult couple actually came out to them all (before only Sayaka knew after all). Sensei only had an issue with telling them because they were her students if I remember correctly.
Again, as I mentioned before, I am not at all surprised Sayaka got a girlfriend in college. Not showing her design at all is a bit mean, but I guess Nakatani was just teasing for the novel.