I was hoping to see that they would just drop the entire database, and then implement hashing from here on out. Otherwise, the apology feels sincere and I appreciate it.
"So, as a clear signal of our commitment to your privacy, we’ve deleted the entire collection of user uploaded contact information from our servers." That sounds like exactly what you were hoping for.
So, they haven't changed their implementation, they've just added the ability to opt out of the poor implementation.