Sure, they'll define what a model airplane is. Most likely, it'll be anything under 55 pounds that's not being used for commercial purposes.
you are forgetting it was the FAA that came up with models flying
400'EverywhereAlways,
yet you left that part out of your 'most likely' scenario of what the FAA will require.
Do you have some special insight as to why the FAA will REVERSE ITSELF
on the
400' Everywhere Always it currently has as an AC?
You also seemed to leave the 15000 DIYDrones autonomous recreational aeromodeling guys
as part of our hobby,
is that what you figure the FAA will do... just accept any NonComercial <55lb toy airplane
including the 15k DIYDrones guys?