I think it’s highly unlikely S4 continues into pre-patch. The new talents and abilities changes would greatly affect arena balance which affects titles and mounts.
As for arena/honor points and gear, it seems likely to me that it’s going to work the same as previous seasons of TBCC. Rating requirements are removed, S4 gear will be available for arena points at a discounts, S3 gear will be available for honor.
Edit: Nevermind I’m wrong. See here: Burning Crusade Classic Season 4 Ends August 29