It's a general principle that the ToS has to conform to the law. (In other works the rules of DMA preempt whatever rules are in the ToS. If the law explicitly

It's a general principle that the ToS has to conform to the law. (In other works the rules of DMA preempt whatever rules are in the ToS. If the law explicitly says that parties can agree to opt-out of specific rules, then the ToS can say - in those specific questions - something different. More/less strict, better for one or the other party, etc.) As linked by `johnnyanmac`, the DMA summary site explicitly says that gatekeepers have to allow 3rd parties to inter-operate with their services.