Why does Xamarin.iOS get updated when WinVS gets updated?
You can control your update installation mode and whether to download updates or not through the Tools > Options menu by changing the settings on Product Updates page. You are probably using auto download and install config, so when an update is available it is downloading and installing VS and Xamarin updates.
Your response seemed reasonable, but didn't impact the scenario. VS still wants to force an update of the SDK on the Mac.
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