Is the pulsar map on the Pioneer/Voyager probes only meaningful for earthlings?
You aren't missing anything. The pulsar map is fairly useless unless the spacecraft is found within the next million years, when it won't have got too far from the Sun (the probes will have travelled about 30 light years in that time).
The problem is not so much that the set of pulsars won't be visible, because they almost certainly would be if you change your vantage point by a few light years, but that the pulsar activity might cease. Pulsars have a limited lifetime and most likely will have stopped being pulsars in a million years or will not be identifiable from their pulse periods. In addition most pulsars have very high velocities, so they themselves will have moved by $\sim 10$ times as much as the probes.
For something of use beyond timescales of a million years they could have used a network of globular clusters, although again the motions of the globular clusters would need to be accounted for.  It's a tricky problem when everything that's close enough that that their positions would change if you move of order hundreds of light years are themselves in motion. And of course the Sun is moving around the Galaxy too.