Niantic released the list of which anomalies are going to be grouped together in an easy to digest chart. They did forget to put Bucharest on it, but edited their post with confirmation that it was a mistake, and not intentional. Because Bucharest WILL cut you. So good catch there. Stitches are no fun.
Cassandra Prime will be the first set for the July 28, and Aug 25th Anomalies. The other 3 quarters have not been officially announced which will be which, Name wise. Though if you watch the video closely, it seems to suggest it will go in order of Cassandra Prime, Recursion Prime, Darsana Prime, Abaddon Prime.
You can see the list below: