Taken from this thread as its a good summary:
https://www.disboards.com/threads/security-from-gch-into-dtd.3566199/
-GCH Front Door Entrance from Valet/Street: Restricted to GCH Guests and Reservation Holders only. No more walking through Grand for non GCH guests through the front door.
-GCH to DTD Entrance/Exit: No changes except addition of two metal detectors. Any general public can still come or go freely at any time, guests or not. PPH guests can still use this shortcut back to the PPH hotel through the Grand.
-GCH to DCA Entrance: GCH room keys still required before 11am (changed from all "resort guests"). PPH, DLH and other non GCH guests must use main gates before 11am to enter DCA. After 11am they are letting all through as usual. Policy is that it is only for GCH guests all day, practice is that they stop enforcing that at 11am. (but you can not still come in through the front door of the GCH)
-DCA to GCH Exit: Open to all to go into GCH, guests or not. PPH guests can still use this shortcut back to the PPH hotel.