Im talking about as replacements for buried radials, not new construction. A new certification was required and as I said there were often power reductions required.
Could you please post the specifics (call letters, links to FCC documentation etc ) supporting your statement?
The FCC requires minimum r.m.s.field intensities at 1 km for the classes of AM stations, but I'm not aware of any maximum field intensity for a given licensed power.
A class C "graveyard" AM station (1 kW, non-directional, 24/7) can produce its minimum field using a monopole of less than 90 degrees and an r-f ground of 120 x 1/4-wave buried radials, but is not prohibited from installing a 1/2-wave or 5/8-wave monopole that, for the same applied power could produce a field at 1 km that is over 1.5X the minimum value required by the FCC.
Decades ago I was the CE of such a station (1 kW non-D on 1400 kHz), which used a 1/2-wave monopole.