They are definitely a prototype, Brooks have said as much.
Likely a variant of their new DNAamp foam (bouncy PU) but maybe not quite tweaked right yet. Levitate 2 will be brought forward as v1 sold out so well, look out for Ricochet (lighter levitate) plus Bedlam alongside.
New DNA loft in other models such as glycerin and ghost (full length and heel pad respectively) which is basically just superDNA but 1/4 lighter -> just soft and light Eva. Expect variations of DNAamp as well in different models.
Launch is the only current brooks even worth considering IMO, ricochet and others might be decent, plus their spikes are quite nice I guess.
Oh and no more posting from the brand that invented the medial post. Guide rails on everything as they try to pioneer the ‘pronation isn’t bad after all as long as your knees and hips are working’ approach to the market. Expect similar things from Saucony if they get their marketing team to listen.