Often on these group tickets, N seats are purchased in advance, with some discount from a cheap fare, but the names aren't transmitted to to airline until close to departure. However, if these are RT tickets and the outbound has been flown, the names have been assigned.

I'd worry more about the mechanism of checking in at the airport and getting a seat there. If the group leader does the check in, friend might not have the opportunity to request a better seat or to pay for an upgrade. OTOH, some groups wouldn't like/permit a participant getting an upgrade for himself/herself. They want everyone to sit together in the back.