as i understand, the fm signal, due to its nature of changing rate of
phase change generates a number of sidebands. Filtering these
sidebands would mean that a band-pass filter is being applied to the
fm signal. That would amplitude modulate the signal as well.

I think you have a point here. Removal of one side of the set of sidebands
turns the FM signal into a sort of AM/SSB signal. During transmission, FM's
robustness to impulse noise will be lost. The presence of a limiter in the
receiver, will turn the signal + noise back into a corrupted DSB FM signal
for demodulation.


Sverre
LA3ZA