I am not sure I understand this. I have a S22 Galaxy Ultra. I do not see anywhere in my settings to turn on or off wifi-calling. Did we already get an update disabling this? I have googled this for about 10-15 minutes now and none of the results match anything to do with my screen settings.
FYI if you bought your S22 Ultra in the US, it probably isn't necessary. Only the European models were shipped with the Exynos chipset and would be vulnerable. The US version was shipped with a Qualcomm chipset, so it shouldn't be an issue.
(This is what I recall on the top of my head though, so you might want to double check this info)