I'm still not sure what the overall effect will be after the update, but I just had a career league team finish with 223 + plays (and 19 - plays). Of course, they also had 181 errors, so we were pretty much a defensive wash. It was still pretty interesting to see just how many + plays you can rack up when that's the only thing you care about. (The team finished with 84 wins and a playoff miss.)
It will be very interesting to see how many you can pull off post-update if you're really trying.