Tor noob here: How are exit nodes actually assigned to end-users though? So far my understanding was that the assignment happens automatically without any conscious descision by the end-user. If that's true, construing an "agreement" would be pretty hard - if the user isn't even aware they're using your service.

Same reason shady companies still at least need to make it look like they asked your agreement and can't just state "by looking into our general direction you transfer ownership of all your worldly possessions to us"