The new CBA also has a provision that if a RFA player does not sign a contract by December 1, he cannot play during the season.
WRT players "owned" (e.g., RFAs) by a NHL organization, if they are not under contract, they can play in European leagues. But the IIHF does not allow players under contract (in North America or Europe) to play for an organization/league other than that.
Two examples of the above.
In the 02-03 season, Kyle McLaren was very unhappy and refused to play for the Boston Bruins. His rights were traded to San Jose and he signed in January 2003. Under the new CBA, his rights can be traded, but if he wasn't signed by 12/1, he'd be out for the season.
Alexander Korolyuk was taken to arbitration last summer by the San Jose Sharks. The arbitrator awarded a one year contract worth $1.2m. Korolyuk decided to play in Russia this season. When and if Korolyuk ever decides to return to the NHL to play -- regardless of his age -- he owes the SJ organization (or whoever they might trade his rights to) one year of service (at $1.2m).