The claim that music should be tuned to A = 432 Hz rather than the standard 440 Hz is widespread in cymatics-adjacent circles, usually attached to assertions about natural resonance, sacred geometry or health. Neely, a bassist with a conservatory background, does something almost nobody in the argument does: he implements the proposed systems and listens.
His finding is that most justifications for 432 require unusual tuning systems for the numerology to work at all, and once you build those systems they sound noticeably out of tune by any conventional standard. He tests versions drawn from "Sonic Geometry", from chakra-frequency tables and from the Verdi tuning argument.
Worth being clear on the underlying facts. A = 440 Hz is a twentieth-century convention, not a law of nature; historical pitch varied widely, and there is nothing wrong with tuning to 432 if you like it. What has no evidential support is the claim that 432 Hz is uniquely natural, healthier, or aligned with the universe. Neely gets to that conclusion by ear rather than by argument, which is why this has nearly four million views.