The following applies to virtual accounts:
As per https://developer.nylas.com/docs/connectivity/calendar/virtual-calendar/#how-virtual-calendars-work we do not send out notification for virtual accounts. To do this you will need to use the following endpoint https://developer.nylas.com/docs/api#post/events/to-ics
Notifications via Scheduler are handled by Nylas.
An update to the /events endpoint will use the provider to handle notification to the participants, ensure notify_particpants=true