"Heteronormative undercurrent" only means for me the very strange nature of the entire premise, the legal marriage stuff. The main character writing a column in some magazine or website about getting married to a woman, as if it's this weird, unusual, exciting thing. But then being open about not actually loving the person, too... A premise like this in real life, even if it happened just a week after gay marriage was legalized in Japan, would feel bizarre and pointless, and it feels weird to me even in this fluffy comic.
Not to argue about the institution of marriage, which is like a whole big thing I'm sure gets argued about all over this site, but does signing some papers and wearing rings actually, really make them any different than roommates? Legally, yes, but in any other sense, I don't see how anything changed. That comic from a while back, "Wife and Wife," was way more appealing to me because it was actually about the domestic life of a gay married couple, even if they were legally not married.
I know this is just a dumb comic and one I can't help but subscribe to anyway, but this is one of my main niches for fluffy GL comics.... :'( I think I'd probably be in love with this story, honestly, if it was literally the same in every way except that they were actually romantically involved from the start... Or if the comic continues after they finally get together, but that one is probably not happening, knowing Yuri Hime.