I do not have statistics and can only speak from personal experience; and my experience is almost strictly related to my archdiocese, which happens to be in one of the most, if not the most, unchurched states in the Union.
As part of adult RCIA over a nunmber of years, I have taken candidates and catechumens to Mass at St Patrick’s in Portland (we are a parish about 15 to 20 miles away, 20 to 25 minutes travel mostly by freeway). While it did not have the Mass from the 1962 Missal, it had the current Mass in Latin, and at the time (up until a couple of years ago) had an absolutley crack choir, who knew and sang both Gregorian chant and older music such as Palistrina.
Each year, and each group, had mixed reactions to the Mass, and there were always some who raved about the music, and the air and attitude of solemnity and reverance. I always pointed out that the Mass was availabel each Saturday night, within easy driving distance, and if they chose not to belong to that parish, that they certainly would be welcome to return.
As best I can determine from asking them later, none of them made one return visit to the parish. It certainly was not an issue of accessibility, as it was mostly freeway to the parish.
Why? They grew to know parish members, and they became involved in the parish in which they joined (St. Francis, in Sherwood). Perhaps unsaid was a degree of laziness. Perhaps it was the fact that our parish is not goofy; our pastor, a Jesuit, is in his 70’s and not one to dabble in liturgical experimentations. Perhaps it is the fact that we have both 24 hour Perpetual Adoration and an active social ministry.
Who knows? My experience - limited, I will grant to all - is that St Patrick’s was not kept under a bushel basket, was not hard to get to, and was most definitely not SRO. People much physically closer were not flocking there.
From that, I think that there will be interest in the Mass according to the 1962 Missal; but I have a hard time seeing that there is really much demand in the area for a pemanent, constant attendance by a large group. Time will tell. I am not threatened by the wider availability of the 1962 Missal; my experience is that many people find the vernacular very important. I also find most people have a very blank look if one starts talking about comparisons between, for example, the various Canons of the Mass; they simply do not have an intelectual or theological basis to even follow what is being talked about. To a large extent to the people I have met in the pews, reverence is as reverence does; they can sense greater (and lesser) degrees of reverence but they do not seem to have an attitutde that Latin is particularly more reverent in and of itself.
Will the 1962 Missal have a come back? I have no doubt. Will it be a good thing? Anything that brings more reverence to our worship is a good thing. Will it have a lot of people at the beginning? I would not be the least bit surprised. After the newness wears off, will it continue to attract the same number of people? I can only speak from personal experience, but so far, none of my experience points that way. But then, time will tell.
It may well be that on the West Coast our experience will be different than areas, say, in the South, or the Midwest, or the East Coast. That, too, may enter into the equation.
(nor should they be)