I've never been on the Miracle but have sailed on several other Carnival ships and just recently they have increased their programming to include most of the major channels. It wasn't that long ago where the T.V. selections were very minimal, i.e. 3 channels.
It's just a guess but I believe TV reception has improved because the apparatus to keep a dish zeroed in on the satellite while the ship is moving has improved considerably. Though some people might think the cruiselines limited TV reception because they don't want you sitting in the rooom watching TV when you could be about the ship spending money. And that may be valid too.