Well, the five priests who signed the brave US-Vienna declaration started "operation survival of the True-SSPX", whilst "Bp Fellay and his gang" (© Bishop Williamson) seceded from the true society of Archbishop Lefebvre since years. So materially "Bp Fellay and his gang" started their own society, the Neo-SSPX aka New-SSPX (which is not so new, because it's basically just a FSSP-II).
It's like Vatican II B with the true Church and the Newchurch.
In practise the True-SSPX has a solid number of supporting US SSPX priests who could join sooner or later, and there's a recruiting of traditional priests from all over the world. Suppose Bishop Williamson would be expelled from the Neo-SSPX and would follow the invitation of the True-SSPX to join the US resistance center, there could be a new seminary of the True-SSPX, and a traditional school, and so on.
If this is God's will, we'll see it come true.
If it's not what God wants, we'll see other things. ... like The Chastisement? :-)