Prior to the update, I could move the remote desktop would open in the monitor where I clicked the Connect button. So if I wanted my remote desktop on the primary monitor, I would just move the app to that monitor and click connect. The same would work for my secondary monitor.
Now, post creators update (version 15063), it doesn't matter where I move the application, it always opens on my higher resolution display. I've tried changing which monitor is my primary, but it still acts the same way.