You're right that this is, strictly speaking, a function of signal rather than sampling frequency. But mansr's model is looking at the best case resolution which is, clearly, a function of sampling rate in a band-limited digital system. I should have specified that though. It's perhaps more important to note that this is a also a function of signal amplitude, but since such discussions focus on full-scale impulse or step functions this falls away.
Even with these caveats the timing accuracy of 16/44.1 digital is at least an order of magnitude greater than even the most accurate analog system.
My bad, I did not follow the link, was working from memory. And as JJ pointed out it should really relate to signal bandwidth though again the equation's the same. For amplitude, you could stick "*A" in the denominator to match the usual form but by convention we assume full-scale signals to "b" bits. There are (much) more complex versions but this is more than good enough to prove your point, that all of us agree with, regarding timing resolution. Seems "they" always manage to get that wrong...