It would seem so.
I think "Mac" entered the jargon many years ago. Is there a difference in "Mac" and "Mc" in a name?
I recall a "Frazer" episode in which his brother is chastising him for the "McSessions" he provides over the phone. Were the writers sued I wonder
Technically, there’s no difference; the shorter is merely an abbreviation of the longer—an actual Gaelic word, “mac”, which is always written longhand in the Gaelic languages (Scots Gaelic, Manx and Irish).
I can see McDonald’s getting litigious over a current-use actual trademarked name, but the Gaelic word for “son” as an all-encompassing trademark does not sound like the company’s domain.