It's an old joke, when a switch (or any electronics really) has 365+ day uptime rebooting could kill the power supply during its POST power supply test.

Realistically you shouldn't have to worry about it, those are solid switches. I have a 3524 from 2001 that's still running, it gets bounced about once a year when I bump the power cable while recabling. I also have a 2960G that's on a UPS, and without logging in I couldn't tell you the uptime