popacrobat
Rock n' Roll Doggie FOB
It sounds like a mix of studio and previously recorded live tracks, maybe with a few tracks being played by crew members.
Not to mention nobody has seen them enter or exit the arena yet, and god knows people are watching.
And we have full songs, but nobody's heard Bono talking on mic between takes? Or stopping the takes mid song? Or letting the band play while he directs? It's not like we haven't heard recordings their rehearsals before. This doesn't sound like that.
Chances are it's just 1. techs dicking around, 2. the techs using recordings from U2's rehearsals recently in France. Or previously used/recorded tracks. There's no way they're actually there right now.