Lewguitar
Old Know It All
It's complicated. But it started with the rotary switch in 90's guitars like my CE22's.Not sure why these stock pickuos would have been out of phase considering there was no coil splitting.
One pickup needed to be magnetically out of phase in order to get the three split coil sounds of that switch IN phase.
It's still done to work with the PRS switches altho you don't see the rotary in new PRS guitars.