I checked against a tone generator, and realized that the lower frequency was actually 120, not 60, so I’d guess you’re probably hearing that. That puts the higher frequency at 212-214, which I also checked and that range matches what I’m hearing (for 100hz, it should be at around 177-180).
Hanlon’s razor. I myself had no idea that 88 had any nazi-related meaning before I read this article and thought nothing of the title when I first heard it. It seems perfectly reasonable that the dev could have done the same, especially since they were willing to almost immediately change the name and remove all existing promotional material once they found out.