Gary Illyes from Google announced on Google+ that Google will be changing who they notify via the Google Search Console (formerly Google Webmaster Tools).
Gary said that for most messages, they will send them out to less people based on the "owner" of the specific verified site.
So instead of sending the notification to the owner of the properties, it will just go to the site owner.
This example, given by Gary, explains it better:
Currently, if the site https://example.com/dont/panic/have/a/towel triggers a message, all of the following sites will be sent the message:
https://example.com/dont/panic/have/a/towel (the site triggering the message)
https://example.com/dont/panic/have/a
https://example.com/dont/panic/have
https://example.com/dont/panic
https://example.com/dont
https://example.com
With the upcoming change, only the owners of https://example.com/dont/panic/have/a/towel will receive the message triggered by their own site.
But for all critical messages, such as if your site is hacked, those messages will still go to everyone listed above.
This change will happen in the "next few weeks," said Gary Illyes.
Forum discussion at Google+.