This is weird. Why would UFC lie about height, weight etc? In WWE it is understandable, they like to make out their wrestlers are all superhuman, but in a legitimate sport? Don't get it.
As much as it is a sport, it still has to make money. Whereas you and I will watch every fight put on for us. Those not as interested are more likely to buy a PPV or watch a free fight if they hear its two 6'4 beasts going at it, rather than two 6 ft guys.