As noted, Gary Cassidy of Inside The Ropes reported earlier this week WWE will not be broadcasting a live Christmas Day edition of SmackDown on December 25th.
As a result, WWE talent is not expected to travel or work on that date. SmackDown will still air on that night, but WWE will have to tape it on a different date.
According to The Wrestling Observer Newsletter, the show will either be taped on December 22 or 23, with the 23rd being the most likely.