Congress is debating the law which allows Directv to keep grandfathering DNS to people who have it, and offering it to people in the 12 markets where they don't offer locals, and there has been some discussion that they may require Directv to cover ALL markets or lose their right to offer DNS.
Directv is probably wanting to collect information on how many people actually NEED DNS so they will know how much they will be affected the law changes and they are forced to either spend millions to cover those 12 markets (if that is possible at all) versus how many customers may leave if they were no longer allows to offer DNS.