Hi anabanana,
I've not found any connection to Abriachan so far. I have various MacDonald lines, and hit a lot of brick wall's. I'll explain a few and try to keep it short.
My granda's father had a grandfather named Alexander MacDonald, and my granda's mother had a grandfather named James MacDonald. I believe these two were brothers, making my granda's parents 2nd-cousins!
Alexander MACDONALD Head b. Abt.1805 Parish Of Urquhart, R&C
Jane FRASER Wife b. Abt.1805 possibly Ardronich/Ardrannich, Kiltarlity (Glen Covinth near-ish Abriachan)
Janet MACDONALD Daur b. Abt. 1826 Parish Of Urquhart, R&C or Kiltarlity
James MACDONALD Son b. 28 Oct 1828 Balchraggan, Kiltarlity
Alexander MACDONALD Son b. 15 Apr 1831 Bishop Kinkell, Urquhart, R&C
The death of the father at Kinkell Castle (interestingly) in 1877, gives his father as Alexander MacDonald also, but no mother's name was known. That's as far back as those MacDonald's have gone, but the Alexander MacDonald b. 1831 married Jane MacDonald, the ship carpenter's daughter from Clachnaharry.
As already discussed here Jane's parents were...
James MACDONALD b. 20 Sep 1816 Clachnaharry - Ships Carpenter
and
Ann MacKay b. 15 Oct 1814 Dochgarroch (again, not far from Abriachan!)
At the time of Ann's birth, her father Donald was a blacksmith in Clachnaharry, while her mother was named Hannah MacDonald. They are given in the 1851 Census as living in Ardendrain, Kiltarlity. Both their birthplace's are given as the parish of Fort Augustus. I haven't found anymore on Hannah's line.
James's father was John MacDonald, a ship's carpenter from Clachnaharry, and Jean Grigor/MacGregor. John is most probably the one buried at Kirkton Of Bunchrew, but I can't get that all important confirmation that I could then follow back to Glencoe. I went to visit the burial ground, it's lovely but the MacDonald graves had turf grown over them, and the writing is now barely legible. So that's another brick wall.
On my mother's side of the family, I've also found MacDonald's, but they were in Sleat and Strath on Skye. I visited the Clan Donald archive there briefly, and found a direct line to the chiefs of the Sleat MacDonald's (17th Century). What I found more interesting though, is my MacDonald's from Strath are supposed to be descended from Glencoe MacDonald's who escaped the massacre, and ended up on the Shiant Islands, before Skye. Skye seems to have a distinct lack of OPR's to help researching this.
So I haven't yet found a direct connection to Abriachan MacDonald's or Glencoe, but I get the impression most of my MacDonald's living around the Inverness/Kiltarlity/Conon area in the early 1800's, probably migrated up the great glen in the previous decades. That's purely speculation for now.