Like many things, the "taunt" is in the eye of the beholder.
One man's celebration is another man's taunt. Unfortunately, when it comes to those in authority "cracking down" on [a thing], sometimes that emphasis can come off as heavy-handed. Especially when it's subjective, case by case, and subject to interpretation.
Celebrations are allowed. When that celebration is in a certain proximity of an opponent, or facing an opponent's sideline, it has now apparently crossed the line to a "taunt", allegedly. Or not. Depends on the ref, depends on the game. It's maddeningly inconsistent, but it's one of those "by god, we really need to DO SOMETHING!" sort of things, so "we'll make a RULE about it! and put EMPHASIS on enforcing that new rule!"
What's the rule?
"We'll let you know when we see it!"
And THAT is the issue I have with it. It reeks of revenge for having to allow celebrations again - which, you might recall, the owners also tried to clamp down on once upon a time.