Among those 8 guys are PoVey and Daniel, two guys that the coaches feel comfortable with playing either position even though one of them has obvious limitations at corner. As such, if you're not in the 2 deep, you're not on the plane.
To me, this is similar to Blackmon playing scout team last week. We should want the best of the guys who aren't traveling to be the scout team players. That said, I'm with you. I can't figure out how a guy who with a week left in fall camp was looking good to maybe grab a starting spot is now not even in the 2-deep. Gotta be frustrating for him, but hopefully it only motivates him to be even better.