The Extraordinary use of the Roman Liturgy is certainly gathering momentum in the US. The Cafeteria is Closed draws attention to the fact that even Notre Dame University—scarcely a bastion of traditional Catholicism—has resolved to introduce a weekly Old Rite Mass on Sundays, which will be sung twice a semester.
The whole issue is more open in the US, of course. For a start, they have got some bishops who are more than half way Catholic—in the sense that they understand the importance of tradition, being in communion with the Church through the ages, and do not see "Catholic" as referring simply to communion with those alive today.
There is also, I suspect, a rather more independent spirit on the other side of the Atlantic, that is willing to give things a try, rather than simply yawning and saying 'well, that won't work, so the answer's 'no''.
There has always been a good groundswell of support for religion generally; religious people are not on the back foot all the time, and it is still possible to bring up a large, loving, pious
family without ones' neighbours thinking one is weird. This has led to a lot of people simply finding in the usus antiquior a better expression of what they have always believed.
There's probably a lot more.