It's a huge waste of time and resources and mass panic while everyone searches for this bomb that doesn't exist, and if you want to sneak in a real bomb, it's super easy to do if you just have 6 other people claim fake bombs first. It's not illegal right?

The two should have different consequences. Maybe look at it like the joking statement of having a bomb in certain places isn't illegal itself, but causing extra concern and panic requiring actions to ensure there isn't a threat has its own penalties. The intent of what you say or do is very important. Shouting fire in a crowded area when there isn't a fire is another example of the misuse of the freedom that could cause harm to others.

The original source of the "fire in a theater" example comes from a court case where a defendant was charged with passing out flyers opposing the draft into the first World War. The case was later overturned because it was not analogous to causing immediate panic or lawless action like a riot. I do wonder how social media's ability to directly influence people into action holds up to this ruling. As an example, one can post an opinion or call to action for something and be covered under the 1st, but imagine a streamer in real time inciting people to riot. Where's the line? Maybe it falls under what I said at the top, it's determined by the consequences and not by some perceived "future crime" that it could cause.