It does seem like the best first steps towards arreligiosity though: the self-inflicted apostasy from any official social religious groups. The path towards atheism will come decades, if ever, afterwards. And it's not even a requirement. I think that an america where most people are "believers" in the most unofficial sense should be a friendly place to secularism.
This mirrors the path towards arreligiosity in Portugal. Back in the 70s, most people were really dissatisfied with the catholic church, for they saw it as aligned with the previous dictatorship. Yet, they remained religious. Their children however, lacking the social environment where belief is bred (the constant forceful goings to the sunday mass, catholic teachings ("catequese"), etc.) were much more agnostics and deists. My generation is mostly atheist (apatheist, in general).