ok465:
(The RWY XX does not have to be selected until you are issued the landing runway and this would appear to meet the 91.129 requirements for 'glide path' as opposed to 'glide slope'. But of course nothing keeps you from line selecting the ILS either.)
Not in the context of 91.129:
(2) Each pilot operating a large or turbine-powered airplane approaching to land on a runway served by an instrument approach procedure with vertical guidance,
if the airplane is so equipped, must:
(i) Operate that airplane at an altitude at or above the glidepath between the published final approach fix and the decision altitude (DA),or decision height (DH), as applicable;
Seems clear
the glidepath refers to the IAP with vertical guidance that serves the runway being used.