Read it again.. They want to go around the perimeter of the room. It's pretty inconvenient to walk the baseboards in a manner that would flatten the cable. Not only that, but the tack strips are rarely up against the baseboards - and rarely are baseboards all the way down to the subfloor.. It is usually possible to lift the edge of the carpet enough to fit cabling into the gap.
Sounds to me like the room is being rearranged to accommodate this new TV, which would mean that the receiver is being moved..
Bellbound - 50 feet is no big deal, and it doesn't require any special/high end cable. However it DOES need to be RG-6. Home Depot sells a 50' pre-made RG-6 cable with ends already on it for like $15. Otherwise they also sell RG-6 by the foot and you can put your own ends on (don't use twist-ons). I would also recommend that if this is connecting to a wall plate at the original location, that you install a right-angle adapter.. Makes for a neater install and there's less chance of the connector breaking off if something falls on it.