Let's face it. Bp. Fellay should not have been the superior general of the Society anyway. That's not even taking into account his length of tenure. ABL never intended that a bishop should be elected SG. But somehow he got in.
I see the leadership ranks of the Society filled with priests, (mostly European), who can not bear the sight of Bp. Williamson. I think they have had problems with His Eminence for years, long before he was expelled. The second in command, the German Fr. Phluger, is, IMO, a scarcely disguised liberal. I think he, in particular dislikes H.E. (Read his 8 page letter to the bishop)
But Williamson's real problems came at the time he gave the interview in 2009 to a Swedish TV network. He had been saying similar things about the "h0Ɩ0cαųst" for years prior to his remarks in the last 5 minutes of an hour long interview. Everyone knew, including most, if not all of the bishop's confreres, not to mention seminarians and the lay faithful throughout the world, his views on the h0Ɩ0cαųst, the "gas chambers," the "six million, etc," Williamson was not particularly shy about expressing them. And yet, the SG said that he had never been aware about how H.E. felt on these matters . What a crock of lying ______!
Pope Benedict, at the time, pretended likewise that he hadn't been aware of +Williamson's views on the subject. Pure baloney! It's just that the lifting of the excommunications came at about the time the interview was conducted, late November, 2008,early January of 2009. The affair was fresh in the minds of everyone, and a total embarrassment to Fellay & Co., not to mention the pope. Personally, I loved every entertaining minute of it.
But to answer the question: No, Bp. Williamson will not reunite with the Society, not until +Fellay & Co. are out of there, and certainly not until all the Tribal connections are severed. The SSPX can not survive to continue its original mission until its Augean stables are cleansed.