How to Detect if "Notify Watchers" Was Checked in an Atlassian Connect Webhook?

We’re using the page_updated webhook in an Atlassian Connect app to detect when a page is updated.

We need to determine whether the Notify watchers checkbox was checked when the page was saved (see screenshots for the legacy and new editor):

I initially expected this setting to toggle the minor edit flag in the page version, but that doesn’t seem to be the case:

I’ve checked the API and webhook payload but haven’t found any indication of whether the checkbox was set.

Does anyone know if there’s a way to determine this? Any pointers would be appreciated!