One of the things that I have noticed as a huge change that has a lot of pro's and con's is the intuitive positioning of AI players in regards to give 'n go and skating around on the cycle. Say, as a RW, if you cross over to the left side on the break out the RW will intuitively skate to the opposite side, and if you are in the offensive zone, an AI skater will skate out of position to cover your spot while you roam. As a forward this is really nice because if you try to clog up the slot or screen the goalie, there generally won't be an AI on your team who just gets in your way and tries to do the same thing, it will go to the right place. However, on Defence, particularly in the offensive zone, but also in the defensive zone too, if you skate up to the top of the circle to get open for a pass, shot, check, or just to keep with the flow of the play, I've found that your partner will skate over to your side to cover, leaving their own entirely open while you're maybe 10 feet in front of them.
Obviously this is a feature that EA NHL will be keeping their eyes on and it will likely be adjusted through tuners as the year goes on but it's one of the bigger changes that I've noticed as an avid player of EASHL.