Could a flag not have been thrown for taunting or premature celebration or something?
I’m surprised it wasn’t.
I think it could technically be a foul but it's not the kind of thing I think the NFL is interested in penalizing anymore. It's two teammates celebrating together, not necessarily trying to show anyone up, and it's not obscene in any way.
A couple of years ago? Yeah, they would have flagged that, probably.
Are they still penalizing for “pre-planned” celebrations or has that all been done away with?
It's a team sport, players should absolutely celebrate with their teammates.