Canon is applying for another stacked sensor patent, this one appears to have storage cells in the substrate to help facilitate fast readout and what seems to be nearly if not global shutter. While global shutter isn't mentioned specifically the patent describes a process quite similar.
The pixel storage occurs in the secondary substrate eliminating one of the main problems of current single chip global shutter designs where both the pixel and the storage has to occur in the same area, limiting the amount of space the pixel can take up which causes dynamic range issues. By moving the storage to the substrate, you remove the problem.
Japan Patent Application 2018-232728