The point is that if the MIDI file and the synthesiser in question are all on the same system (i.e. a VST in a DAW), no MIDI data transfer has to take place. So the data transfer limit in question isn't applicable.
Even if it's on the same system your piano still has 88 keys and you get either a loudness gain per key or a phasing effect when a key is played more than once per time. The only somewhat interesting effect (at least for some) might be that the generator hits its limits (usually 20 to 40 notes polyphony) and randomly decides which notes to leave out or prioritize. But this is out of control of the "composer" and likely not the intended effect.