To my knowledge, the KZMZ downgrade was simply a result of:
1. CC consolidating KZMZ's xmitter with KRRV & KKST to avoid paying extra rent
2. As a result of the lower height, KZMZ did not meet the height requirements of a class "C" and was downgraded to a "C0"
Having said that much...not sure why Regent didn't try to move KFTE further north, away from KMYO, maybe to Church Point or the KLWB tower and get a power increase. It would allow them to put a city grade signal into Opelousas, Eunice, and Ville Platte. Signal is decent in the car in Opelousas but marginal on a tabletop radio. Eunice and Ville Platte are much tougher, especially when there is any sort of atmospheric enhancement. I can't see which other station may prevent them from increasing power.