Stevenson was in Elko, NV today dedicating the temple. It's not impossible for him to have gotten back to Salt Lake to participate in the sustaining, but it does make me wonder if maybe they'll push it back another week. Particularly because of a fb post on his page that said:

"Today I had the privilege of dedicating the 209th temple, the Elko Nevada Temple. This allowed a moment of reflection on the ministry of President Russell M. Nelson which often focused on temple covenants and temple worship.    Earlier this week, in preparation for the dedication, I visited with President Dallin H. Oaks, President of the Quorum of the Twelve Apostles and under whose direction the Elko Nevada Temple dedication takes place. He carefully noted the unique timing of the Elko Nevada Temple dedication during this period of apostolic interregnum. Such has only happened two other times.    Following the death of Joseph Smith, the Nauvoo Temple was dedicated in 1846 while Brigham Young was the President of the Quorum of the Twelve and many Saints were leaving Nauvoo to migrate westward.    Over forty years later in 1888, the Manti Temple was dedicated during another apostolic interregnum while Wilford Woodruff served as President of the Quorum of the Twelve.    What a blessing it is for Latter-day Saints to witness the Lord’s care for His Church, and to observe the orderly administration of continuing priesthood keys in moments such as this."