That's odd. The collation of both the user and system databases is case-insensitive?

I guess it's possible there were changes around this for contained databases, but system procedures have always followed the case sensitivity rule of the database you're connected to at the time, AFAIK. Does the problem appear/go away when changing the compatibility mode?

Does the following query bring back any databases with a case-sensitive collation?

SELECT DISTINCT collation_name FROM sys.databases