I suppose it's the definition of the sandbox boundaries that are in question at this time. Things being flown by non-pilots above the ground is nothing new.

Why didn't the Feds just push drones into Part 103 with some additions? Drones seem much less imposing that an UL flying in airspace. UL are allowed up to 254 lbs (powered). That would be one big-a drone.

https://www.eaa.org/en/eaa/aviation-communities-and-interests/ultralights-and-ultralight-aircraft/getting-started-in-ultralight-flying/about-faa-part-103-for-ultralights

(b) Notwithstanding any other section pertaining to airman certification, operators of ultralight vehicles are not required to meet any aeronautical knowledge, age, or experience requirements to operate those vehicles or to have airman or medical certificates.

But, yes of course, the basic "yield right-of-way" of any aircraft still applies. Judging from your screen name, I'm sure you know the FARs give the least maneuverable aircraft the most right-of-way, regardless of their mission.