In terms of visuals this update is lacking so much. Take Serie A for example. They did update the kits, but for some reason the majority of teams don't have any sponsors. Looks better, but kills immersion for me. Parma player kits have the correct sponsor but the goalkeeper kit doesn't. The Turkish league is even worse, just a few of the top teams have 20/21 kits but the vast majority of teams doesn't even have updated kits. This is just from what I've gone through now, I'm sure there are more teams who were supposedly meant to be updated in this data pack. National team kits have been updated though from what I've seen. All UEFA nations and Chile as well. I know I might be nitpicking but it also annoys me a lot how they have face models from previous games but don't/can't add them in after a certain date. Davy Klaassen, Mario Götze, Marco van Ginkel examples of players who are in game now and definitely had a face in older PES games but they won't be added until the next data pack. This happened last year too for players like Ibrahimovic. Imagine that, Milan at that time one their main partner clubs, signing a club legend and one of the most recognisable players in world football and he had a generic face in game for weeks. Again, I might be nitpicking a bit here but in my opinion this lack of care on their behalf is just really indicative for how they work on this game overall.
A second thing I've noticed is that Other European Leagues is now full of teams we can edit. These are all the teams who aren't supposed to be in the game anymore like Hull, Livorno and Wigan, but with fake player names etc. I wonder if they'll remove these later on or not. I hope not since it could be used to edit in more Europa League teams for example.
Now to actually play the game a bit and see what's changed there...