I checked on the spec sheet for my UPSes (CyberPower) and it says 60 Hz +/- 3 Hz, i.e 57 to 63 Hz.
BTW, how do you know when Tesla completed this change and you could run you test. Did they send you a message?
In my case, yes they sent me an email stating they had completed the change. I asked them if they would contact me when I reported the issue and asked for resolution on the feb 20th, and the tier 1 rep told me "they will let me know when they have resolved it for you, and I will reach out and let you know".
In my case, it happened exactly like they said it would.