I don't think that the delay in display is new. I came to that conclusion a long time ago based on tracking via the web and tracking directly with the AC ops system. Trip.com also speaks of the display as "near real time".

I just checked AC124 which was due to leave YEG at 1700. It actually departed at 1708 [according to the AC web site]. Trip.com at 1709 said that it was scheduled to depart in 16 minutes.