The athletic dept is not saying "we've sold our allotment", it's something to the tune of "progressing towards selling out our allotment." The demand does not appear to be there and they are deflecting by putting a positive spin on it. If they've gone from 5000 to 5500 over the past few days, then technically it's true that they're progressing towards selling out the allotment. If the AD was really close to selling out, say, over 9000 sold, they'd be spouting off with those numbers. "Only a few hundred tickets remain, get yours before they're gone." Or something along those lines.