Whole Crew Mic'd?
 

Watching the Kentucky/Miss St game, it looked like the entire crew was mic'd up. Why would they all have headsets? Alternates in case of injury? Or do they have some sort of comm system between themselves and/or the booth?

It's crew comms.

Several SEC crews are using this system on an experimental basis this year. Our state has used it during HS championship games for the past two years.