Not sure. I still have 4.3 installed on my S4 (AT&T) and don't have any issues with in. Not sure what's the reason why AT&T pulled out 4.3. But if they are going to revise, i'm sure they will revise with a different code so that even the 4.3 users will be able to update to the revised one.
Do you have a source that the update was pulled? I keep hearing this but I can't find anyone with any information when I Google it. I was lucky and got the 4.3 update and really don't have any issues.
EDIT: When I looked last night I couldn't find it, this morning a few articles popped up though from SamMobile.