My impression was rather that he indicated that GD had a problem with blink during that time. He writes that blink "always has idolized GD", but also uses a few examples that indicates that GD wasn't very easy to work with during the Pop Disaster tour due to some power moves. He writes that it was a lot of tension, but that GD "absolutely smoked them" at a lot of the shows, which made blink want to up their game as well. He describes Mike and Billie as "the kindest, coolest people during the day, but that the mood switched as set time rolled around" (p.223) and specifies that Mike was always very welcoming and cool to them. He mentions Tré as more leery towards them and describes it as a territoral thing, but he also writes that blink has kept asking GD for a rematch tour, but that GD has kept refusing. He adds that: "but we're always friendly when we see each other. They're the rival gang across town who we both despise and respect" (p.225). He's writing it in a humorous way. Earlier in the book he also mentions how he loved Dookie, waited for it all day and that he was waiting in line to get it. 

What power moves or like asshole moved did GD actually do?

Mark writes that blink were supposed to close every show even though they were co-headliners, and writes in general about how difficult a tour of that size is to manage because of lawyers and managers etc. He mentions that the closing act was responsible for "going all out and take it all home" and that it was a agreed on that only blink were supposed to use pyro, but that GD decided right before the first show that they wanted to do pyro as well. The other example he uses is that GD refused to enter the stage before it was pitch dark outside, and also refused to cut their set, which made it difficult for blink to play before noise curfew, that Mark explained the problem to Billie, Billie said sorry and promised it wouldn't happen again, but did it anyway. ? Mark doesn't write it in a disrespectful way and he doesn't call them assholes or anything, he just states that GD was "out for blood" and that he sees it like GD didn't like to be reduced to an opening act.

Wow lol maybe GD were assholes 

Thanks for replying, and in such detail, I really appreciate it. I think it would be hard to be welcoming and buddy buddy constantly, especially on a tour like that where you're living on top of people. Though I remember watching the behind the scenes thing at the time and thinking, I bet Green Day insisted on playing first just to show up Blink182 ?