I would also add that you need to start this culture at the beginner level. We have two feeders. 98% of our attendance issues came from the feeder where band is a "fun" class where everyone gets a 100 and coming to the concert is "expected" but there's no consequence for missing except a stern look the next day. Those kids are shocked when they have playing tests for grades and consequences when they miss a concert. Kids from the other feeder have experienced the same policy as the high school for 3 years already.
I don't care if a student is a senior drum major all-stater soloist, if they miss a performance for a dumb reason (emergencies etc excepted) they're out of the show and quite possibly out of the band.