Do we know what the plan is for the lead group to go out in?
And what the planned for pace is for that second group?
Mo might (correctly) figure that the early pace of the lead pack is just NOT the OPTIMAL pace for either winning or for his best possible race.
Further, if he emphasizes going for a super-time and doesn't achieve it; he's set his fans and himself up for relative failure. If, pre-race, he emphasizes something a little more modest; he's set he and his fans up for a high probability of success; i.e., "He did (way) better than he hoped / expected."
Overall, I don't see enough here in what he says to get too worked up one way or the other.