No. In fact the proposed regulations specifically disallows drones from using ADS-B unless they have filed a flight plan and the pilot is on radio with ATC, or certain other exceptions. This is due to concerns about overcrowding the ADS-B spectrum.

It is unfortunate that “NextGen ATC” hit its scalability limit just a few days before it became mandatory.

Maybe ADS-B-v6 will save us ;)

I don’t believe aircraft size matters. It depends on what airspace you operate the aircraft within.

Perhaps relevant: https://www.youtube.com/watch?v=gnSeOR3nnx0 [avweb discussion of ADS-B requirements]