It is a huge buff, but it seems alot of people haven't noticed this change!
It isn't in the patch notes? Then it's probably a bug! Nerf Mindbreaker!
For real tho, I still don't see much use with it even with this huge buff, maybe against Sprint Burst it's good, but then if Survivors have eyes they could just start walking when they see you coming, also with Mindbreaker Survivors could intentionally touch the gen and hold their Exhaustion at 99 so they can use it on command.
It not being in the patch notes makes me think it wasn't intended and will be changed. Hopefully not though because it's much better this way.
It's also no longer in the perk description. The again, I never used Mindbreaker (cause of how god awful it was), so I don't know if it was ever listed in the original perk description.
This makes it so pig doesnt have to worry about SB off gen at least!