FC upgrades #1
 

I was flying from Montreal to EWR the other day and wanted to get on an earlier flight. The outgoing flight was in B, return in Y. I was told that since the outgoing flight was in B, my entire itinerary is treated as if it was B, including changes. I can understand that, but do you know if similar "downgrading" policy exists for FC upgrades?

I'm not sure that I understand your question, but getting upgraded does not affect any fare rules if that's what you're asking.