Hard to know where then phrase originated, but the closest early reference seems to be from Brendan Behan: "There's no such thing as bad publicity except your own obituary."
Mark Agnesi's video proves that saying is wrong. A friend at TDPRI said it's the most alienating video he's ever seen, and I agree. It's already wiped out any goodwill the new ownership had been given. Nothing good will come of it from Gibson's standpoint.
Trademarks can be invalidated, and thanks to what happened with Fender, it's definitely possible with Gibson. In 2004, Fender was granted trademarks on the Tele, Strat and Precision body shapes, a group of about 20 smaller builders (ironically led by Stuart Spector) challenged the trademarks on the grounds that the shapes had become generic years earlier. In 2009, all three trademarks were cancelled by the Trademark Trial and Appeals Board (TTAB).
What's important about that ruling is that TTAB ruled that it was a precedent. Most of their decisions apply only to the case being considered, but since it was a precedent, that should make it much easier for Dean and its allies to win.
I'm just wondering if Gibson will respond at all to this giant pile of shit they've stepped in.