this has been said as a false rumor.
And another part of your post has me bothered. To say that Story takes back seat to gameplay in the other genres shouldn't be true. Two of the most successful RTS's in the world have had an EXTREME amount of attention placed on their story. Similar with FPS. Half Life, Deus Ex, System shock... Hitman even- These are all on the "Must Play at least one of" lists you'll ever see. Why? because they have good immersive gameplay but they also have a Brillaint story backing them up.
so yes story is key to an FPS or RTS even if it's flimsier than a well used dollar bill.