Dave Meltzer mentioned on the latest edition of Wrestling Observer Radio that FOX originally wanted the TV rights to RAW when they first started talking with WWE.
The situation was described as unique because WWE had multiple bidders at the time. NBCU, the parent company of the USA Network, had the right to match any offer, which they did, leading to FOX getting SmackDown instead.
NBCU didn’t match FOX’s deal for SmackDown because they spent a lot of money on RAW. The reason FOX originally wanted RAW was due to it still being the A show for the company.