I'm not 100% sure that is the case, but if someone finds something to that effect, please share. The law talks about "possession" by minors for licensees and to that end they often do prohibit minors after a certain hour or some other restriction. It is clear though that those with a CPL should be ok to carry, oc or cc. I find it very hard to believe that alcohol sales would be a primary source of income for an organization that gets a lot of donations in the form of tangible assets AND charges $3.00 to get in.
What is really sort of karmic about the whole ABE issue is that by fighting and arguing with us, the commission and ABE executives have guaranteed that there could possibly be a larger number of OC people, and probably just everyday people carrying firearms, in attendance than there would have been if the commission would have quickly and quietly removed the firearm prohibition from the contract. Now they are very likely that they will get individuals showing up who would never have considered even going to this event. The incessant need for our "representatives" to prove that one is "right" despite evidence to the contrary often is the precursor to REALLY getting what they don't want.
Minors under 17 as far as I can find - MCL 750.141:
http://legislature.mi.gov/doc.aspx?mcl-750-141
750.141 Presence of minor under 17 in places where liquor is sold, given away, or furnished; attendance of minors at dances.
A minor child under 17 years of age shall not be permitted to remain in a dance hall, saloon, barroom or
any place where spirituous or intoxicating liquor, wine or beer, or any beverage, liquor or liquors containing spirituous or intoxicating liquor, beer or malt liquor is sold, given away or furnished for a beverage, unless the minor is accompanied by parent or guardian. A proprietor, keeper or manager of any such place who permits a minor child to remain in any such place, and a person who encourages or induces in any way the minor child to enter the place or to remain therein shall be deemed guilty of a misdemeanor. This section shall not prevent a township, village or city from establishing, by ordinance, regulations more stringent than the provisions of this act relative to the attendance of a minor at theaters, movie houses, bowling or billiard halls and dance halls. This section shall not prevent a township, village or city from establishing, by ordinance, regulations permitting the attendance of minor children at dances where no spirituous or intoxicating liquor, beer or malt liquor is sold, given away or consumed in the dance area.