Comment 2 for bug 177508

That seems to be the case if you are subscribed because you are the assignee. That doesn't still fix this bug because:
a) the info message (you are now subscribed to foo) doesn't say why as bug mail says (you are subscribed because you are subscribed to a duplicate bug, or whatever)
b) if you are just subscribed to a blueprint, instead of put as the assignee, there will be no info

I've just asked on IRC for someone to subscribe me to a blueprint, and this is the message I got. As you can see, I can't guess why I'm subscribed:

You are now subscribed to the blueprint packaging-tools-usability -
packaging-tools-usability.

--
  https://blueprints.edge.launchpad.net/ubuntu/+spec/packaging-tools-usability