The only outcome that seems plausible is that all personal drones are grounded. For maybe ever.
I built some non-compliant (also non-autonomous) 450g drones before the 250g weight limit. They’re only for acrobatics at treetop level or below. It’s kind of silly IMO that this style is required to have a transponder now. This is speaking as someone who flies planes.
For the store bought ones that require no forethought - I am glad those are regulated.