Some kids have edgy phases, some kids have melodramatic ones.
The whole "take care of your friends" has a doulble meaning, in the "getting ready to leg it", but also in the "I've just realized I've been an asshole to mine", what dramatic wording Nezuna.
If Kotoyama wnat to set up more things to explore later, those coversations with all of the vampires would be a good way to do so, we've met Hatsuka's kouhai, chatted with LoveGreen again, got to know Kabura better and secured Haruka a place in the main cast.
We still have Nico (with the princess character I expect Kotoyama to come back to for another "growing up sucks" storyline) and Seri, then maybe Azami and Susuki is where we'll get back into the shounen stuff if the author prefers.