I'm not convinced this is anything but small sample sizes and exaggerated perceptions as a result. Yes, the testimonials keep coming. But what about the many - I'm speculating with some certainty - game owners who do not experience this phenomenon? They'd be less likely to post and, if so, not in any great number. As a rule - my own

- the silent are often the majority except in situations of obvious flaw or controversies of unusual import and interest to the larger community.
That being said, I'm currently in the playoffs, having won the first round and now beginning the league championship or, in my world, the Deference Series. I may indeed end up experiencing what has been portrayed here as an AI lift, or a morale influence. If it's the latter, I hope it does kick in. Most of my team is feeling Good to Great. All season, I've let my excellent manager take charge of almost all game decisions. In the first round playoffs, I did find I needed to 'pick up that phone' and override his decision to start our #5 pitcher in the fifth game of the best of five. Too much riding on it, and I went to the #2 guy on instinct. He threw 8 innings, 8 strikeouts, performing marginally above what I'd seen him do regularly throughout the season.
Part of me wants to believe in real 'characters' in play during the post-season, prone to all kinds of human proclivities to shine or bust during the pressure. The argument isn't limited to only human-controlled influences. If the AI players/team are able to find that virtual stuff that drives them over the top to victory, then maybe I should be saying, "Man, they brought it in the last series!" or "This team (mine) does not believe in clutch -- and they prove it every year by losing!" rather than, "Ya think there's a bump in the playoff settings?"