From what I've understood, the lock-on mechanic on its own has been changed so it's no longer as easy to abuse the backstab system, in PvP or PvE. This is more than either of the two souls games have done. It might be enough to make 1 vs 1 PvP more than just constant backstab fishing, but IMO, backstabs should stay in PvP to punish poor stamina management. And only that. If you have stamina, you should be able to avoid a backstab. In Demon's Souls, this was the case, because a roll would make a backstab attempt do 0 damage on you.
But for 1 vs 2 or 1 vs 3 encounters, the changes to the backstab system don't sound promising. It means the lone person will have a harder time getting backstabs, while the three fighting him can easily circle around him for a BS while he's fighting another player. Not only that, but even -if- the 1 person lands a backstab, he'll die before the animation is finished from a few spam R1's from the other player or players.
In other words, it sounds like they're making 1 vs 1 PvP more fun, but at the cost of making 1 vs 2 fights impossible to beat.