Microsoft is sure taking its time with the announcement of its rumored foldable Surface devices, but the company may have a good reason for this. The latest USPTO patent detailing an improved hinge system for foldable devices points to the fact that Microsoft does not want to release foldable devices with half-backed folding mechanisms similar to those plaguing the initial Samsung Galaxy Fold wave.
https://www.notebookcheck.net/New-Microsoft-folding-Windows-device-patent-reveals-elegant-hinge-solution.426562.0.html
Why even bother? Google is folding their tablet, soon Samsung, LG, Nokia, etc will follows. I think Microsoft is wasting their money on folding tablet running android .