King struggles against elite quickness and elite speed. But if Stokes was playing better I think they'd have him on the field.
Also based on what the DB coach said, we'll probably see both King and Stokes on the field at the same time when the game plan calls for Alexander to be in the slot. So it's not just King over Stokes it's also Sullivan, at least if you assume Alexander can play the anywhere fairly well.
As far as the Lions next week, the game plan will be stopping the run and TE Hockenson... though the Lions did ha e 3 WRs about 50% of the time, but I'm thinking they keep Alexander on the outside and go with a Safety or Sullivan again.