Let me explain myself better.
Refs already spend time being coached - watching videos, and breaking down decision criteria. Not sure if it third party video i.e fifa resources, or local club replays if it materially matters.
Reviewing video's post game might not be as effective feedback - it might reduce the number of assessments made, given that the assessor is watching all of the game in person, not just where the camera tracks, so to be effective, you'd probably need more time per assessor per game to view the game and then a replay as well. (remember, they are assessing all match officials, not just where the ball is/ camera is following).
I really like working with the assessors. I feel a lot of the value is in the discussion about key match incidents directly after the end of the game/paperwork is done - delaying that to a few days / hours later after a replay is watched might not be as effective.