I think we need that. I added that to https://github.com/puppetlabs/puppet-postgresql/pull/95 because puppet run failed creating custom data dir if the parent directory isnt owned by postgres like /.
@fhrbek wrote it didnt work for him like I did it, as I made a mistake. You have to ensure that the top-most non-existing fodler in the path is created/owned by postgres before initdb runs. 
However, my patch ensured that the top-most folder existed and owned by postgres, like /postgres