You must not have much exposure to alt right groups and or 4chan, because you can’t scroll through those for more than 5 minutes without seeing a reference to Boogaloo.
To be clear, I’m not some deep Internet lurker, but I’ve known the term for about 5 months (circa the Pizzagate news), and whenever I check out a place like that, usually in response to a news story, I’ll see it there.