The restaurant may not be offering pickup service in a way they consent to because Grubhub is listing them against their consent. Grubhub isn't being clear that these restaurants haven't consented to orders via Grubhub.
This is just reiterating the first post I responded to, and so I'll respond in kind:
Why does Grubhub have any responsibility to obtain the restaurant's consent? If I pay someone to go to the grocers and pick up some items for me, is that someone obligated to obtain the grocers' permission? Why is this situation different?
If the restaurant is offering pickup service, then to me there is no obligation on any third party to obtain permission to utilize that service and deliver the results to a customer.
