The ability to choose default email notification settings on a user by user basis seems obvious. While there is a vocal group here looking to eliminate the individual email notifications - for good reason, it is obvious that HubSpot simply yielded to the “squeakly wheel”. While that ship has sailed, for future reference, fixing issues is always appreciated but not so much when you arbitrarily do something for one set of users while undercutting another set of users.
Put the user in control to configure these defaults to fit their workflow is basic UX and should have been the step taken.