Yes, it is correct that some years ago the Utilikilts didn’t have snaps at the waist. I have 5 of them, purchased between 2002 and 2008:

2002: Standard, Black, zipper (no apron) - 2 snaps at the waist.
2003: Original, Postal Blue (apron) - no snaps at the waist = you had to wear a belt to keep it up.
2005: Original, Black – no snaps. Design wise the 2003 and 2005 models are identical.
2007: Original, Sand - 4 snaps at the waist
2008: Mocker, Olive - 4 snaps at the waist.

Accordingly the change to snaps must have happened between 2005 2nd half and 2007 1st half.

Greg