I think it’s pretty clear that Shiryu will indeed be impervious to most CoO users, Fujitora is debatable but if Film Red power levels are accurate, you have characters like Shanks who can just cancel someone’s CoO lmfao, characters being impervious to certain forms of Haki may very well happen and Shiryu may be one of them.
If King is basically impervious to most CoA, not sure why people take issue with Shiryu being impervious to most CoO. Lol