It's actually canon that masrur thinks of her as a little sister and tells people that in one of the bonus comics so yeah not happening
I'm not even a little bit worried about MasMor. For the shippers, guys you got a cute moment, good on you, enjoy it! I feel sympathy, I do, because Ohtaka herself stomped on that pairing so much, genuine shippers are really hard to come by and it is discouraging to watch a pairing you like be stamped as "NEVER GONNA HAPPEN" by the actual creator.
But canonically, they have their similarities, which are just adorable and I love their relationship, but I know what I see and MasMor is just not going to happen. It's been rejected and fooled around with too much. They have a good relationship that's platonic and I love it that way. Just because you have "compatible" genitals doesn't mean that you're prime candidates to engage in romance. Bromances and familial bonds do exist.
It's cute, but not going to happen.
That being said I do think that AliMor shippers are going a bit too far as well. Dude, so fucking what, you're trying to tell me after almost 200 chapters of development and bonding on a deeply emotional level their chances have gone sub-zero? Gimme a break.