I don't think so and here is why I believe that it doesn't apply. Armor AC now applies to mundane and magical attacks so the armor is protecting you. Someone in heavy armor is not going to try and dodge the attack at all, they are just going to stand there and take it and pray that their Armor stops it. That being said, 6 dex means your going to be god awful at dex saving throws so any spell that doesn't target AC (fireball) is going to cook you in that armor you rely on.
Personally I think this is a step in the right direction. Someone in full-plate isn't going to even think about dodging. They simply should not have the maneuverability. They may try to parry or block but any block that gets through they are counting on their massively protective armor and not any ability to dodge. However by doing so they are constricting their ability to take any action that requires dex. They can't attack well at range, they can't save vs anything that targets an area unless they roll really well and unless their a dwarf they also move slower. Also, their initiative is going to take a hit as well as Dex skill checks.
I think that Dex is such an high powered stat that having Heavy Armor not take a hit to AC from dex would be a marginal power boost. Your sacrificing all of the other (and very numerous) benefits that Dex offers for a boost to AC. Seems like a fair trade