Well, people around here don't fully understand what a retcon is.
People could argue that pre-retcon Jean Grey ate a sun. But that's ignoring the fact that the retcon established that as a seperate character which was never really Jean. It was ALWAYS(due to the retcon) a seperate entity when it was Dark Phoenix. The Real jean was in the ocean. So there is no (Pre-retcon jean grey ate a sun) as that never happened in continuity.
Like here. The retcon establishes that the character was never really that powerful. I don't care what the reason is, be it that LT or TOAA let him at that point in time. Or that it was an illusion, or a dream or some mass drug induced delerium. It's not important the why. Just the fact that the retcon happened means that it didn't really happen the first time around the way people think it did.
In otherwords those that argue for the pre-retcon MM not only ignore the fact that Pre MM Retcon LT is not in this fight. But they were duped by the illusion/dream/trick/drug induced stupor.
Just as there is no "pre retcon-jean grey who ate a sun" there is no "pre retcon MM who was higher than current LT" It never happened.