Guys, I worked it out. It's the Heisenberg uncertainty principle/Fourier conjugate.

Let's say you send a yo now, and then you're going to send another one in 5 minutes. Then you decide to send a third in between. How much information does it contain? Less than a full timestamp's worth, because the timing is constrained.

Once you are sending yo's at the maximum line rate (certainly at least every nanosecond, it's such a critical piece of infrastructure), sending or not sending an individual yo is down to one bit of information. The time component is basically completely gone.

In other words, you cannot know the precise position of a yo at the same time as knowing the precise momentum.