Things have changed after Summorum Pontificuм in 2007 and Universae Ecclesiae in 2011, just as Bishop Fellay expected and predicted, and as H.E. wrote in a letter. The signs and fruits of that are all around us in terms of many conservative Catholics coming to Tradition. I predict that movement will only grow stronger over the next decade, with tens of millions more Catholics doing the same.
You say above that you predict tens of millions more Catholics doing the same; that is, conservative Catholics coming to Tradition. I'm not that hopeful. I live in the largest city in the Northwestern United States, and there are a little less than 200 registered families at the local FSSP parish, which is less than what they started out at when they first arrived here in 2008. The numbers have also dwindled at the local SSPX chapel.
While the numbers of those coming to the diocesan TLMs may be increasing in some areas such as San Diego, I don't see an overall trend of an increase in Novus Ordo Catholics coming to Tradition; either through diocesan TLM's, or the SSPX.