However, it's unclear whether it would be pitched as a follow-up to those devices or a new product in its own right.
The associated diagram sheds more light on how it might work:
In the patent's notes, Microsoft added that "the user can separate the device portions and use them individually. As such, from one perspective, the present magnetic hinge assembly implementations can be viewed as virtual hinges."
The magnets mean the device would secure in place with a click and sync immediately, but at the same time both screens could work independently as tablets. It would also offer greater more flexibility than is available on the current Surface lineup.
The upcoming release of the Surface Duo and Surface Neo proves Microsoft sees a future in foldable devices, and this latest patent only serves to emphasise that.
Of course, it's worth add that only a small percentage of designs that companies patent ever make it onto the final versions of their products. Nonetheless, it gives a window on designs the company is considering for future hardware.
If something does come of it, I just hope we don't have to wait so long between announcement and release as we have with the Surface Neo.