The DJ, Mr. Rochon, states in his written on-line response to this that he has photographed over 1,000 events over the past four years, and has used them to market his business, and the business of photographers. And this is the first time he has run into a big deal with exclusivity. Seems strange to me though that he uploaded 232 photos from the event, and he "gifted" those photos to the bride and groom. He alleges that the only way to market wedding-related businesses is by using photography...
This is a weird situation. The way I read the short excerpt was that the photographer's contract was between her, and the wedding couple; of course we did not get to see the entire contract, but the quoted excerpt mentioned "the parties"...but did not mention OTHER parties. Who knows if the contract the photographer used was iron-clad and really legally bulletproof; from what *I* read, it's not...seems to me that if that's all it said, there could be other contracts. I'm not sure on the legality of one service provider being able to legally bar any other vendor from doing things that are legal, like clicking a shutter.
As is always the case on f/stoppers, the reporting and fact checking is of very amateurish level. I've seen so much useless clickbait from them that I do not consider anything they write to be reliable.