Tricky topic. Tesla does advertise that summon can be used to park your car into tight spots, so in that situation, dog mode should remain on as the car was going into the user's desired park mode.
On the other hand, summon does constitute as the car moving, which is a valid mode for disabling dog mode. Though that is more of a stretch as one should focus on the end user's need rather than a mechanical state. This is software, after all, and it should be smart enough to know about the end user's needs.
I would vote for dog mode to disable when the driver returns and put the seatbelt on, not if the car moves from summon.