Are you sure the old version did this? I thought submix view always operated this way. I am not sure why this would matter in any event as the highlighted channel in the output row clearly shows which output is selected. Maybe I am missing something.
You know you can double click the playback channel name above the fader to rename it, right? So if your bass is on PB channel 1/2, rename it "BASS" *above* the playback fader (same as you did for the output row). The channel name below the fader shows what *output* channel is selected, which again is already shown in the output row in submix view. I renamed all my active Input, Playback, and Output channels and run several mixes regularly, and it is very easy to know which channel is which.