They've cut out the middleman and will just trick you directly. I don't have an account but I use it a lot for discogs. Everytime, it goes one of three ways.

1) They have a prechecked "Create Account" option, so that completing the purchase creates an account.

2) They use the classic "big, bold button" dark pattern, so that completing the purchase creates an account.

3) They require creating an account to complete the purchase. I've cancelled orders over this one.

It hasn't even been a progression. I've seen all three recently, and which one I get seems to be a dice roll.