In recent months/years there have been many times when Guides will simply make that recommendation from a better safe than sorry angle. As in "I don't know what incentives will be offered next week but just in case it's better than what you have now, wait a few days before returning the paperwork."
Typically they really are not told what will happen in advance. And when they are given information in advance, SOMEONE usually spills the beans. The fact that it hasn't happened so far adds to my own skepticism.
This time could be different. Time will tell.
Incentives really aren't that good now so it really wouldn't surprise me if better offers materialized. But incentives typically aren't communicated via staff meeting. I don't personally consider new incentives or price increases to be "big announcements."