I was really sad to learn that the Database Diagram function is being removed from the SSMS-18. I find it EXTREMELY useful in the database modelleing and buidling. I hope that you will take it back into the SSMS sometime soon.
Is there any way to run an older version in parallell to the new one in order to be able to use the Diagram-function?
Please consider adding your for to the collective issue at https://feedback.azure.com/forums/908035-sql-server/suggestions/35746747-database-diagram
Rob Wood commented
I very much agree, I use the Diagrams feature all the time, either while designing schemas or for producing quick documentation to assist others.
Dietmar Mueller commented
Let the database diagrams be inside ssms!