What I'm talking about isn't just potting.
For instance, I have a strat set right here in a cool replica build, zero potting as requested. Will it squeal? Yeah, I guess if I play with gain. But when you play with the guitar, all the little things like flipping the switch or hitting the body are relatively quiet, barely come through the amp until you really crank it. Yet, the old strat with the grey bottoms, all the extemporaneous noise goes right to the amp and when I moved those pickups around builds? That attribute stayed the same.
My '64 335, same deal. '62 pat sticker pickups and '64 harness. It's all vintage, no potting ever, every part now 60 years old. But it doesn't have the level of microphonic my '68 Riviera has. You flip the switch on the 335, tap the body, etc, barely comes through the amp. It's quiet like that. Yet, The Riv? You hear the toggle clank more, hear the guitar louder through the amp if you just tap on the body at the same volumes, etc.
Who knows, that might mean the pickups are going to short out soon, lol. But, it's definitely a thing and it adds just a little something on the note attack IMO.