Advertise this for what it is- with special guests KOS- and it would appeal to some of the 'die-hard' fanbase, but only because of prior knowledge and a rough idea of what to expect. Surprise everyone like they have done, those expecting a Bon Jovi show can rightly feel pretty miffed.
Then there is the 'casuals' that are often held up as reason/excuse when setlists come under fire- that show certainly wasn't for them. So has Jon misread what people are saying about mixing it up, and did he feel that show was "for the die-hards"?

Anyway, it goes ahead. Bobby gets to do vocals on some songs. Why isn't David doing some songs? If they're gonna do this kinda fun, mixed up show, why not really go out there and let everyone have a piece of the action?

Would Richie have sang a few if he was there? I wonder how long this has been planned for- if we go with the theory Richie's issues are related to how he felt about WAN and the bands direction, would news of this been the point he thought "Jon's jumped the shark here?"