Originally Posted by
hydrogen
Why would OP be more likely?
Aren't both wait lists (gate waitlist and pre-gate wait list) rank listed by time of request? So SE trumps E75 trumps E50, etc.
If not, nobody knows the upgrade algorithm, so it is possible that OP could pay the M fare premium and still lose the upgrade lottery.
If he is E50 on M, he would have better change then any E50 on any other Flex class.