I love Cape Breton music! I listened countless hours to Jerry Holland albums back in the 80s, and spent many an hour listening to the music live at various music camps.

In that MacKenzie Brothers clip, when there's just the piano and fiddle it really sounds Cape Breton to me, but when the piper comes in he's playing in the normal modern Scottish style that you'll hear in any good pipe band. If you heard a Grade One pipe band (be it SFU from BC or FMM from NI or Shotts and Dykehead from Scotland) play that first jig, every piper in the band would be playing it exactly like that fellow is playing it, all the same fingerings and ornamentation and timing and style.

If such a Cape Breton piper was playing in an archaic style brought over from Scotland in the 18th century and perpetuated through the generations, I would expect to see old-fashioned stylistic things, playing more in line with Joseph MacDonald.