The suggestion makes sense for some cases, for the others it does not. <...>
Instead of mass emails, Bitcointalk admins could set a reminder in the forum
News line.
Then I suppose much more people with hacked profiles would know that there is a way to restore their accounts.

It makes sense but maybe I got your ideas wrong initially. For active users, who have hacked accounts, I believe they know how to recover their accounts, by openning threads in Meta, and there will be so many legendary users will give them helpful advices with process to recover accounts.
Initially, I thought of your suggestion is for people who have hacked accounts and have not yet logged in their accounts on the forum for too long. Did I understand your suggestion too bad?