It does not matter if they disclaim its truthfulness What matters is if they adhere to its teachings There are some within the Church sadly who do not believe the Book of Mormon to be true  rather they believe it is inspired nonhistorical scripture or that it contains good teachings Some of these would say the Book of Mormon is the word of God others may not However they adhere to its teachings and would thus be classified as adherents to Mormonism   I agree that CoC are moving farther and farther away from Mormonism but until they completely turn away from the history culture and teachings they are still a part of Mormonism Please note I didnt say they were Mormons but rather adherents to Mormonism The term Mormon in its connotation is narrow enough now to refer to members of the LDS Church and its th century offshoots not most of the pre offshoots It is NPOV to say they adhere to Mormonism But not to say they are Mormons I am willing to stand by that unless convinced otherwise  feel free to ask your friend