Gordon, I don't know if you are still getting WikiTree feeds. I did not respond to this in late 2020 as I was doing some additional investigation and then got sidetracked. You are correct that nowhere in MacLean's Account does he state Malcolm Macleod came to the colonies nor does anything infer that he did. This was an error on the part of the researcher who wrote and compiled the paper.
This statement is found in the research. "...Malcomb Macleod Rasay who was born in 1711. He was sixty-two years old when he was secured as a guide and interpreter for Boswell when he made his tour of the Hebrides Islands in company of Samuel Johnson. Malcolm MacLeod was an all-around man, stout and well built, a good sailor, guide, trader and could speak Erse and English fluently. He was a valuable asset to Boswell and Johnson as they sailed forth in 1773."
Edit: wrong item pasted into the comment box. This is the continuation which may be complete fiction:
Flora MacDonald, the Lady who got Malcolm out of prison, was living in Kingsburgh during Boswell and Johnson’s tour. “Here she was visited, in 1773, by the celebrated Samuel Johnson. Her husband, oppressed by debts, was caught in that great wave of emigration from the Highlands to America. In the month of August, 1774, leaving her two youngest children with friends at home, Flora, her husband and older children, sailed in the ship Baliol, from Campbelton, Kintyre, for North Carolina” (J. F. MacLean(1900, An Historical Account of the Settlerments of Scotch Highlanders in America, prior to the peace of 1783, together with notices of Highland Regiments and Biographical Sketches, Helman-Taylor Co., Cleveland, John MacKay, Glasgow, 1900, p. 395). Of course, when Mr. Johnson visited Flora he was accompanied by his guide, Malcolm Macleod. Dearest friends, this visit would have been a delight for both Flora and Malcolm. They undoubtedly discussed the future and Malcolm would have told her all he could about America. It is probably no coincidence that Flora and family decided to escape the hardships of Scotland for a better life in America. Malcolm MacLeod returned to America at this same time, and likely travelled with his close friend Flora to North Carolina, where he too was somewhat of a celebrity. “Flora’s fame had preceded her to that distant country, and her departure from Scotland having become known to her countrymen in Carolina, she was anxiously expected and joyfully received on her arrival. Demonstrations on a large scale were made to welcome her to America (ibid).