No, but I never entered my key into the other one.
Still an Alt account.
Old pre-Auth accounts still count as an original.
Basically if you're not on your original account then you're on an Alternate account.
This includes if you had an original pre-auth account, and then changed to another pre-auth account (now authorised).
I've never made an Alt, even pre-auth.
Suppose I never thought I'd need one. And prepping for needing one kind of gave the feeling that I'd assume I'd need it. And if that were the case then I must assume I was going to do something wrong.
But I suppose if I did get perma-banned for whatever reason I might make an Alt. But I wouldn't be happy about it, nor proud of having needed an Alt.