"legacy Vs new version" question

Yup, me did. On PTR rerolling a legacy Etched Sigil resulted in getting a legacy Etched Sigil and it’s still the same on live, no worries.

The only time I found an old version being updated after reroll was Gesture of Orpheus. The CDR for Slow Time goes down from 70% to 40% if I remember it right.