I would definitely have to say it was more his head-banging, given that Hunt was still active on the show for a good while after Don’s final appearance in season 22, and going through the guides, we only had three showings of Don’s musical skits in between season 24-29, whereas the Mystery Guest skit was shown quite often (and I remember as a kid seeing that skit at least 3 or 4 times) since he doesn’t bang his head on a piano.
For reference - these are the three showings I’m talking about. Yellowstone Park was last shown in season 24, the alphabet song in season 27, and Whistle, Whistle, Little Bird in season 29 (also the last time a Don skit was shown).
There were no Kermit and Don skits aired in seasons 25, 26 and 28. So really, I can sense Sesame Workshop took big caution with airing Don’s skits after he was removed, and the reason we also have his skits commercially is not only for the kids, but for adults who come by for nostalgia.