The first time you open the Ranked Profile panel in the settings, the label below Ranked Profile (on the top side) will always say "Pre-ranked statistics" for the first time it's displayed. Switching to Coven (and then back to Classic if the player does not have the Coven DLC), or reopening the Ranked Profile panel will cause the label to be correctly displayed until the player logs out again.
Screenshot (yes I am actively playing ranked during this period)