Yep. Steam will just reactivate them. The problem with the Unlockables pack is that the only way to disable them would permanently disable all associated awards. That means you'll never be able to get any of the stuff like Killbane's mask/gloves, the respect/cash bonuses, etc. The real problem lies in the fact that the code in the exe itself controls the trigger for unlocks so we can't swap them around like we could in SR2 where a simple table file contained all of them.
The OP's best bet is to contact Steam and ask them to specifically remove the Unlockables pack dlc from his account. That course has reportedly worked for quite a few people.