Though it is true that a lot of older string instruments weren't designed to take the tension of modern strings at modern pitch, and some of them really open up at a slightly lower pitch. I'm building lyres, and many lyre people are from that "A432 resonates with the universe" crowd, so I've been using it — and I can't deny that there seems to be a sweet spot in sound for a lot of instruments at that pitch. I honestly have wondered if there's some physiological reason so many people prefer it.