I doubt customers typically know or care whether you use heroku, Amazon or any other provider. What they want is to see their system up and running.

That said, I wonder if with the heroku postgresql setup, this vulnerability could mean that if even one db is compromised, it could allow access to other databases too. Maybe heroku runs several postgresql db's on the same virtual/physical hosts?. If that's the case, then heroku simply can't afford to let even one database stay exposed because it would risk all others.

Whether or not this is the case, I don't know, but it kinda feels like running your app on a shared-hosting account...