No, the Main L/R meters on the AR mixers are always Main L/R meters. There is no way for that Main L/R meter to meter the input or output of any single channel or bus other than the Mains. The only signal level indicator for channels is the single LED input indicator above the channel. It can give a little bit of indication, as it's both variable intensity as well as going from green to yellow to red.
The only function that switches when engaging PFL (or AFL for buses) is that the Headphones and Control Room outputs switch from monitoring the Main mix to monitoring the Solo bus.
