I was able to change my (very inconvenient: ATL-YUL-CDG-WAW with 6 hours of layover in YUL and 5 hours layover in CDG) outbound routing on an award itinerary to a much more convenient one within 24 hours of departure!
Also, the agent I spoke with mentioned there was plenty of SkySaver availability in business on ATL-CDG route for today, May 30 (no coach seats though).
In short - if your award routing is inconvenient - call back within 48 hours of departure and you may score! If you are PM this does not cost you even a dime.