Just a couple of points to consider:
1)AMC will only use MD-11 freighters as a last resort due to bulk considerations. That’s why you see B-747’s on the AMC ramps. They do like MD-11s for pax work.
2)It is a buyer’s market for B-747’s. (all models) If Atlas \ Polar continues to downsize it will remain a buyer’s market.
3)Evergreen and World have been bidding partners for a long time and have done well due to fleet differences. Perhaps World wants more of the B-747 share now that Evergreen is starting to move toward the supertanker?
4)Over the years I’ve seen companies make statements like this when in labor negotiations. It’s called dangling the carrot here in the states. If I were at World I would be hopeful that what the company says is true, but also wondering how much of it is aimed at getting me to ratify that contract. The World guys certainly deserve anything they can get. Good Luck.