So what has happened to the NPRM process?
I am sure this is the first phase. Recall after 336 came out they issued the "Interpretation of the Special Rule for Model Aircraft." first, and then a few months later the actual NPRM came out. I suspect a similar track is being followed here. But nobody know for sure when the NPRM will appear. They also have to develop the test, work up a process for recognizing Community Based Organizations (CBO), and getting LAANC going for recreational sUAS. Meanwhile they issued AC 91-57B, this notice, and we are all apparently just fine ignoring them for now.