I don't think you'd "deserve" to have hackers unlock it, but I also think that you should have no legal right to prevent people from unlocking it without your permission, and I don't think it's unethical or immoral for anyone to do so. If you sell something to someone, and put it in their hands, they should have the right to do whatever they want with it.
Presumably you've made the choice to bundle the base game and the DLC together like that in order to reduce your costs somehow, and I'm not responsible for your business model or logistical issues. If you're worried about people unlocking the DLC for free, don't put it in their hands without charging them for it.
Either way, I think it's entirely reasonable to classify the concept of "charging extra at a later date for something you've already given the customer" as rent-seeking or overreach. Even more so if, instead of a one-time charge, you choose to charge a subscription for something that does not require any ongoing costs for you to provide.
Presumably you've made the choice to bundle the base game and the DLC together like that in order to reduce your costs somehow, and I'm not responsible for your business model or logistical issues. If you're worried about people unlocking the DLC for free, don't put it in their hands without charging them for it.
Either way, I think it's entirely reasonable to classify the concept of "charging extra at a later date for something you've already given the customer" as rent-seeking or overreach. Even more so if, instead of a one-time charge, you choose to charge a subscription for something that does not require any ongoing costs for you to provide.