No, it definitely was the one that killed it. It's not some sort of speculation. Also how does that work in your head? THIS one-shot is what you imagine would save a yuri magazine from dying? C'mon.
Do you have a source for that ? Some people here said the magazine was already in trouble before this publication so I don't really know who to believe, and I'm pretty curious to read the whole story of their fallbif possible.
And I'm not saying it would have saved it. I just think some people up there thought they could bring some interest back in their magazine by stiring some controversy or attracting new reader who like theses sort of thing. I just don't see why else they would publish a work like that in the first place