I think a lot of people are missing the point the manga is trying to convey by having different expectations and I feel that not enough credit is given (we on dynasty after all)
The whole manga is supposed to be about the bittersweet feelings of romance in youth, and in this case it just happens to focus on Lbgt themes. Of course a lot of us want some more solid ground covered, but I think that's kinda the point. (Also rip time constraints) Young romance isn't meant to be tied up into a neat bow; it's hard, messy, painful, and your not sure what's going on half the time. The future, I also think, is meant to be a bit speculative because their story is done and life is just moving forward.
Hope more people can get into this series without the feeling disappointed that there isnt a proper Yuri couple