From version 10.1.1 both group message and announcement work this way. Users can access group messages/ announcements only which is sent when they are in that role/group.

I have tested above code again and find working.
I have created an announcement to test role RA. Then i have checked if user UA (which user role is not RA) have got that announcement. find that user UA have no access to that announcement. Now i changed that user role to RA and now that user have access to that announcement.

Please check and let me know.