I've explained this at length and it seems you don't even want to even try to acknowledge as you keep asking the exact same questions.
When Grant Morrison says "Batman is gay" in an interview, or really any Morrison interview, that plays into how the fandom relate to his comics. On the flipside consider the very real effect that the Scott Snyder plot dump interviews have had on how we receive his books. Sure, they're just interviews, but without them both runs would have would've been a very different experience for those who were exposed to both.
Fans also react to early promotional or concept art, i.e the new Lobo.
Rumours and leaks influence early perceptions, or even consider the planned death of Grayson in Infinite Crisis, which was overturned but still left many Grayson fans very anxious for a long time after.
Character designs blow-up in social media and cosplay and elevate the character to broader recognition among new audiences i.e Harley Quinn, new Batgirl.
Nothing that comes out of these companies is just "any random thing" - not even one advance promotional image that only exists online - it all contributes to how the fans engage with the core products and it's really just a very basic principle of marketing. And in response to this content columnists will promote viewpoints and analyses and yeah, Twitter and forums have a very real and valid role in shaping fans perceptions and being a conduit for audience cultivation and audience feedback. And if none of this were true and I'm simply talking out my arse, then this blow up never would have happened, because it's just a variant, right?