This is very good to know, incase you get calls that your wireless guest network is broken. The WLC will not redirect HTTPS urls.
Assume for a moment your guest has a browser home page that is https:// (443) or he / she attempts to open a https:// page, prior to the AUP. The user is expecting to get redirected, but nothing happens.
The Guest will sit and spin giving the impression the guest network is not working properly, but in fact the WLC is not redirecting HTTPS traffic, only HTTP traffic to the AUP.