It's an obvious question to ask, but did he elaborate on what these "frustrating things" are? Are there legitimate issues with the narrative/performances/etc. that hamper the film, or is he referring to a "Luke's only in the film for a minute/Han dies = unhappy critical response" type of scenario? Those specific plot movements may indeed be a flaw in the storytelling, depending on how they're depicted, but I can easily imagine people being pissed off regardless of anything.
edit: I'm not suggesting that the dude would straight-up drop such a degree of spoilage in the line right there, but I'm still curious if it's an actual quality vs. perceived expectations sort of thing here.
Also it's totally fitting that toy companies are dictating the creative direction of the film, given that practically the same thing happened with ROTJ.