Not related to recent releases afaik.
For Newsfeeds, it is clear. We do not even take care of created_by in the newsfeeds model getListQuery() method. This should be implemented from scratch.
But for Contacts, I was hoping it would work.
Test instructions:
Create a sub-group of Manager with the following permissions for Contacts:

Access admin interface YES
Create YES
Delete NO
EDIT NO
EDIT STATE YES or NO
EDIT OWN YES
Log in back-end with a user member of that group
In Contacts Manager, create a new contact (You may not have permission to assign it to a user, but this is unrelated).
Save and Close that contact.
The contact is clickable in the Manager (Here the clickable one was created by this user)

Result of click to edit:

NOTE: It works fine for Articles with the same set of permissions. Did not test others.
Not related to recent releases afaik.
For Newsfeeds, it is clear. We do not even take care of
created_byin the newsfeeds modelgetListQuery()method. This should be implemented from scratch.But for Contacts, I was hoping it would work.
Test instructions:

Create a sub-group of Manager with the following permissions for Contacts:
Access admin interface YES
Create YES
Delete NO
EDIT NO
EDIT STATE YES or NO
EDIT OWN YES
Log in back-end with a user member of that group
In Contacts Manager, create a new contact (You may not have permission to assign it to a user, but this is unrelated).
Save and Close that contact.
The contact is clickable in the Manager (Here the clickable one was created by this user)

Result of click to edit:

NOTE: It works fine for Articles with the same set of permissions. Did not test others.