It would help to know what update you're talking about, since nothing is likely to affect changed to the eixm ACL section, which, AFAIK, is the only way to disable SMTP AUTH.
If you don't want POP before SMTP, then you need to untick both boxes for antirelayd in WHM > Service Manager
I don't understand why you'de want to disable SMTP AUTH, but if you want to, you'll have to edit the exim ACL's. You can do that in the Exim Configuration Editor and probably remove the following block from the ACL section:
Code:
accept hosts = +auth_relay_hosts
endpass
message = $sender_fullhost is currently not permitted to \
relay through this server. Perhaps you \
have not logged into the pop/imap server in the \
last 30 minutes or do not have SMTP Authentication turned on in your email client.
authenticated = *