My main problem with the Nibutani/Dekkomori pairing is, and I don't care whether you want to ignore this, that the source material still matters. If they ever finished the story, the conclusion would have to be mostly the same to the novels. There is simply no way they would ever give Nibutani an openly gay ending. Therefore it can never go beyond subtext or bait.
that´d be true if we were talking about canon character from the novel like kumiko and reina from euphonium, people knew that there was no way that they´d end up together, because in the novel kumiko ends up with tsukamoto, but it´s a different case with dekomori she was tacked on the story, there´s no source material for her, writters don´t have a storyline to follow, they can writte anything they want. If at the end of the novel nibutani were to find a boyfriend like kumiko that´d be a different story because in that case the writtes have to follow the novel, but i don´t think that´s the case so at this specific case the source material doesn´t really matter
I mean we all know that no there´s no way nibutani and dekomori end up together(mostly because at this point the franchise is over) but that has nothing to do with the source material, like @TheLostLight already said that just how kyoani works being maid dragon the only exception. That being said the anime does have strong subtext that´s a fact, there´s strong evidence that nibutani and dekomori may or may not be in love, but come on dude we work with less than that nico and maki barely talk at the anime the subtext between yui and azu-nyan is barely noticeable if you don´t use your yuri goggles. If your logic is "if is not on the source material fuck it " you´re pretty much skipping 30% of this site content