It has to be, otherwise you wouldn't able to see the numbers on the scoreboard since they'd be updating at whatever the default tick rate is for TF2 servers these days. 66 times per second or something like that?Using the "bars" icon that cell phones use to indicate signal strength as an indicator of ping is inaccurate anyway. A bad connection is one that's currently being monopolized by some other process, and the best way to tell if that's happening is if your ping is currently rising. Once it starts dropping, even if it's reported as being in the hundreds, you're in the clear, I think because ping is actually reported as an average over time or something.
It's also reported as an average because it doesn't really matter to 99% of the players (most of em probably don't even know what it means).