30 chapters later and Yamato has yet to retract this statement. The editors even put the panel up on the official volume poster. That same volume spread has her looking forward to Luffy as Ace insisted and she's the only non-SH ally there.
Currently, everything she's guessed about Luffy is being proven right and she has a front row seat to witness it. Momo still has shown 0 interest in asking Yamato to stay, but in the spinoff manga the select Carrot fans are reading, their ship is canon.