I never cut any spikes unless they are so long and get in the way and poke me in the eye. really!
I grow lots of phals. I don't find that leaving old spikes on harm plants at all.
Some abort spikes as soon as flowers are all dropped, while some plants keep their old spikes green.
Those old spikes that stay green long after all the flowers drop may or may not rebloom.
I let my plants do their thing. Rebloom do not necessarily mean inferior flowering and I have had even better blooming on the side spikes off old spikes.
I admit that leaving the old spikes on make the plants look rather ugly though.