While Im 'happy' with the ending of this (alt?) side story, the feel isn't there.
However, as a note to all those who claim it sucks, or that the MC is a beta suck... I have to wonder how many series you spread that opinion across.
Now, for my real view.
It almost feels like the mangaka was making a commentary on their own ending with Utaha's 'existing' end of her story that had to be re-written. It was like they where all dolls just following a set of instructions. Mix cake, throw it in oven, see what happens.
While I'd love to see a epilogue or two, it might actually do more damage (I'd read it anyways). I mean look at it this way.
It seems all other girls have 'given their blessing' or 'will let it slide for the night, this one time' and the 'managers' or 'editors' are turning a blind eye that 'nothing will happen anyways'.
And then something does... at least there's that much credibility to is.
As endings go, I have to give it a 5.5/6 out of 10... not fab, not terrible, just 'went with the flow'.