Dunno what the fuss is all about. It's become par for the course to put on entertainment for visiting delegates to special and international conventions. Whilst we have seen events at halls along with very tasteless virtual mobbing of arriving delegates in the past, this is clearly not within an assembly hall and is just a bunch of people having a fairly innocuous time.
I know the WT would have critised Rock and Roll in the past but even the Witnesses are allowed to move on. As for comparisons with evangelical worship, this is not a service.
This type of event does add to a body of evidence suggesting the whole tone of the org has changed and that there is perhaps a more general appeal to emotion rather than intellectual study but at the end of the day it's just a bunch of entertainment.