does refinishing affect the sound?
Well...that depends on a lot of factors. Including superstition, misinformation, voodoo, and varying levels of metal illness.
There's a lot of disagreement about finishes on electric guitars. Some scientifically-minded people maintain that the sound of an electric guitar comes from the metal strings reacting with the pickup magnets, which is technically true. But then the other 99.9% of musicians believe that the wood (and the finish on the wood) is very important.
Without going too far down the rabbit hole, I can hear/feel/VIBE the difference between a guitar with a thick polyurethane finish and one with a thinner finish or a nitrocellulose finish. But that's only with the thickest of poly finishes. I have a six or seven year old Gibson with a terribly thin, extremely shitty nitrocellulose finish on it, and I love it. It sounds great.
The picture is really blown out and terrible, but it's the only way I can show you how bad the finish is. That's wear, those two spots. Usually a guitar would have to be 50 years old to show wear like that. But the finish is so thin, it's just kind of disappearing.
That's nothing more than a manufacturing flaw, but I like (love) the guitar as it is, so I never sent it back or complained when it started to wear away.
All of which is to say that a thin finish (or removing the finish) does indeed "open up" the sound of the guitar. As far as I'm concerned.
But -- I think it only "opens it up" when you play the thing unplugged. Once you plug it into an amp, I don't know. Seems like once you're plugged in all bets are off and it sounds the same as a guitar with a thick finish on it. Or a lawnmower. I don't know, it's all
feel and
sound and
vibes. Hence the voodoo aspect of it all.