Better late than never, to go on first-name basis (one of my criticisms of the final chapter: their true first names revealed in the final arc but never really used... until now, addressed by this epilogue) and another kiss(!) is always welcome in a story that's supposed to have romance in it.
I like that Miyako's hairstyle is somewhat of a middle ground between her (short) middle school look and her (long) high school style. I too admit I prefer long hairstyles, but she seems to prefer it shorter and maybe this is also what Yuuki likes.
Her growing out her hair in high school seemed to be more like part of her "getting out of her comfort zone to try new things" (becoming the titular cutie in the process), and now that she's found what she wanted to do and found the one person she'd love to be with, she's going back to her roots. She's not just a cutie, after all.
Cheers to the (near) future of cohabitation awaiting these two - man, they just stopped short of outright saying "Let's get married" (but I'm sure this is implied, being direct was never a big thing in Japanese culture). Too bad we don't get any more of the other characters, but it's kinda fitting it goes full circle here - we started with just these two and end with them too.