In the first months after the game’s launch, I noticed that you would be given the option to upload a replay of your online matches.
That choice was random and usually included matches that had deciders in the last second. In ranked mode the average was that in 1 out of 10 matches you would be asked to upload a replay. That choice was completely random. Some matches were awful and you could upload them, while others were much better, yet no replay appeared.
Then after a few patches that feature was gone. I played a lot of matches and the replay upload feature after an online match never appeared.
Have the prerequisites changed? That feature always baffled me