I agree with the goal of this but I'm not sure about the approach technoshaman suggests. I absolutely want to be able to reduce how frequently I get automated unencrypted email that includes the full text of access-locked journal entries, while still getting notified, via a medium I check, when I have new comments. So, some variations:

Maybe we should say, no, this is the way things are and if you want more privacy you should turn off some email notifications. In which case I should simply stop some of my email notifications and set myself a reminder to check my DW inbox more often.

Maybe we should make it possible, in the notifications options, to differentiate between getting emailed when people comment on access-locked entries and getting emailed when people comment on public entries -- or, in Notifications or Privacy, add the option technoshaman suggests, to just say "you have a new comment" but omit/suppress message content (and perhaps even omit the name of the commenter).

Maybe we should add email encryption; I could give Dreamwidth my public PGP key and it could encrypt the automated emails it sends me.