I'm not sure about that. Having the third possession in OT is important, because at that point any score wins the game, but that's only relevant if you actually *get* to the third possession. The Chiefs had a serious advantage in knowing exactly what they had to do, and a very big advantage in having four downs to do it. The team that defers doesn't have a punt unit. Furthermore, the Chiefs had no reason to play prevent defense - even a TD could be matched so they could play straight up. After kicking the FG, the Niners were forced to guard against a game-winning touchdown and were basically already in the position of at best conceding a FG from the moment the drive started.
Bottom line, the team that receives is put into a conservative position from the start of OT (on O, and then on D if they don't score a TD), and the team that kicks is put into aggressive mode (on D, and then on O regardless of whether the other team scores or not). And my experience watching football tells me that aggressive play wins way better then 50% of the time. Yes, it beat the Lions in the NFC Championship game, but I'll take the aggressive approach every time based on history.
We don't have stats on this style of OT because it has never been used before, but it looks to me that "receive" is the wrong choice.