They already do this for their commercial accounts. But, the packs are more like content-provider-parent-company packs than theme packs.
DirecTV must do the same. I was waiting for my car to be serviced at the dealership recently, and found the DirecTV remote. I'm not familiar with their channel numbers, so I went into the guide to find ESPN to catch a little SportsCenter. When I hit on the channel I got a message about it being an unsubscribed channel.