Well, I don't know about the Shinto one. Yeah, probably it will gain popularity too in the Shintoism, although Shinto ceremony is usually less chanting more doing something.
A common Japanese person will be borned as a Shinto, married as a Christian (just the externals, lots of wedding chappels there with hired foreigners to preside), and die as a Buddhist.
It is more of a cultural necessity.
Also the job as a Buddhist or Shinto priest is usually hereditary. The family own the temple. So either the son (usually oldest one) will inherit the role, or finding a son in law that will fulfil the job.
