I believe that there's room for different flavors of yuri in the yuri fandom, and that's fine. If I want something more sweet and subdued, I'll read something like Kase-san or one of Nakatani's touhou doujins. And if I just want to see two horny lesbians really going at it, I'll read something from Ayanero Taicho or Mira, and I think that's okay.
We also had the ace character take a good look at Yuu's relationship with Touko and realize that Yuu isn't the same as him.
It's not that Yuu couldn't feel love like she feared, it's that her perception of love was formed entirely by stuff like shoujo manga and love songs, so when her process of falling in love turned out to be a slow burn instead of a big flowery explosion, she decided that it couldn't be love. And this chapter has Yuu pretty clearly spelling out to Touko that she's attracted to her physically, specifically on page 27, so it's not only fulfilling an emotional bond (although that bond is extremely important too).
I think that whether ace people have sexual relationships is probably up to the individual and whatever partners they may have, but I also think that it's pretty clear that Yuu isn't ace or aro.