The ability to subscribe users to a view is a great feature but the permission to perform that function is extremely limited. Currently you must have a Publisher Site role and be a Project Leader for the specified project.
My opinion is that if a user is able to share customized views (an existing feature of the Tableau security structure), then that user should be able to subscribe those people to the views that they create. Being a site publisher and project leader gives too much control of workbooks than I am comfortable giving to all of the people who should be able to set up custom views and subscribe people to them.
If this permission is not tied to the "Share Customized" permission, then I would hope it could be exposed as an additional separate permission. Thanks for considering.
Possible source of permission:
Tableau example of subscribing others:
Community Forum post showing issue: