I don't believe that is the case, I'm pretty sure they're just fixing the problem where Releasing a pet generate hate on things you don't have enmity on. Assauling/Sic'ing a pet on something puts you on the hate list the second it hits the enemy, So you'll still have enmity on it, even if you never personally touch it, Your pet hitting it puts you on the enmity list, Very very low on it, But you're still on it.

I think this is primarily a fix to SMN getting aggro from Super-Tanked mobs when they release.

Then again, If it is how you say, which I would like to say i doubt, I think it'll be more of a nerf than a buff, Since If I'm sending a pet in to suicide, Its so he has the aggro and the Stone comes for me, aggro free, after The pet dies.