470.8000 MHz is alive and well. It rebroadcasts the Fire Paging talk group
Not quite, you've got it backwards.
470.800 is the countywide Fire Paging simulcast frequency, a primary resource. The MCC 7500 consoles at 44-Control key up all 10 base stations directly via the MLC 8000 simulcast controller, meaning the dispatch audio is going out directly over 470.800 with nothing else in between. That same console audio is also multicast on 46.18 in order to support legacy low band equipment that is still in service. It's a single resource on the consoles named
DISPATCH, with the audio going out over both frequencies simultaneously and directly.
The Fire 1 talkgroup is rebroadcast over 470.800 on a secondary basis, meaning fire paging/dispatch always preempts that rebroadcast.
The Fire Paging talkgroup is, in fact, a rebroadcast of 470.800 over the trunked system; not the other way around as you suggested.