Aw folks are SO MUCH better about this here than on Reddit.
They were there last year though not in their usual neighborhood and I heard rumors they had some issues and opened late. Quite probably because of the early dust storms. Last year they were called "Something Freaky This Way Foams."
Also I'm not so sure anymore that they do actually try to fly under the radar or if that's something others have made up. Their foam parties are indeed in the playa events guide and the for-profit business they are associated with has been openly tweeting about them being at the burn and their name and address.
Still I'd like to see the tradition of trying to keep them on the down low continue.