As for the conspiracy theory about Blood Legion specifically, it's a bunch of BS. I was watching Blood Legion's Dexter stream Tuesday, Wednesday and Thursday night last week, and they heard about the exploit for the first time late Thursday evening, their time, and I can confirm with certainty most of their main raiders had not gone into LFR before that point, AND Dexter went out of his way to take potshots at the guilds who did exploit in the stream titles (i.e. "PlayFair.tv", "LOLOLOLOL at exploiters", etc).
And for the "Invite to Blizzcon" thing, I believe several other guilds were passed over due the to possibility of visa issues with inviting TWO guilds to the US, more than likely on relatively short notice. Also, Blood Legion's team is mostly on the west coast, IIRC.