When you look at articles, posts and documents about new features and enhancements in SQL Server 2019 CTP2, you will find nothing about Query Store. However, there are some graphical enhancements in SQL Server Management Studio in the version 18.0, also default configuration for Query Store attributes is changed too.
First SSMS 18.0. From this version, you can see another Query Store report – Query Wait Statistics. When you click on it, you can see aggregate waits per category in a given time interval (default is last hour).
It looks like there have been some incremental improvements to Query Store. I think the defaults also make a bit more sense.