Yup. I have access to our internal documentation so it isn’t a problem. You will find all of this info in the 4.15 release notes once it goes public. 
I don’t mind pointing things like this out. Actually, it is better that our community is so vigilant about finding changes that could possibly be bugs in the engine.
We have already logged dozens of issues with the previews because of our users. Keep up the great work guys!