The higher the sample rate is, the better the compression quality will be. That seems to be the conclusion to draw from several dynamics plugins I've worked with that implement oversampling (in this answer it is mentioned too).
I can fully understand why the bitdepth is important when speaking compression, since it directly controls the number of posssible steps or levels within one sample.
But how is compression quality related to sample rate?
Is it because it allows faster attack times and more accurate release slopes, or what is going on?
EDIT: We normally say that 44.1 kHz is more than enough to cover the audible range of the average human being (~ 20 Hz .. 20 kHz). So in that regard, there is no insentive to go higher. I can understand why going in a little higher will reduce the accumulation of aliasing errors, something that would affect any effect or process of the signal, not just compression.