It should be noted that there will be many small aircraft that will not equip with ADS-B. In fact, where drones will commonly fly, aircraft won't be required to equip with ADS-B, so it's not a panacea.
"As to the airspace restrictions for other aircraft without ADS-B Out, again, operators must avoid Class A, B, and C airspace and not operate within 30 nautical miles of an airport listed in Appendix D. Also, pilots must not fly at or above 10,000 feet msl in Class E airspace, excluding the airspace at and below 2,500 feet above the surface (this is a carve-out for high altitude areas). Also, in Class E airspace, pilots must not fly at or above 3,000 feet over the Gulf of Mexico within 12 miles of the U.S. coastline."