As it says, everytime I switch to Classic Beta it deletes everything but 400 mb or so of data in my retail folder. I have to redownload over 50 gigs of data each time. I wanted to beta test Classic badly and have really enjoyed the time I got to spend in it but I’m not going to keep downloading the entire retail game to do it.
My WoW folders are on one drive and my Battlenet is on my OS drive. I’ve never had issues with retail with this configuration.
Update: As I am downloading the retail version it appears my Classic Beta folder may have been emptied. It only shows 164 mb.