The analysis board is a major "cheat" whether it is legal here or not.
Visualization is perhaps the single hardest thing to master to get to high levels of chess. Being able to "see" what happens after pieces move is critical to being able to assess any candidate moves.
Giving people this board is tantamount to using an engine, imo. It serves a higher level function that books, databases do not serve, and it circumnavigates the hardest part of being good at chess, visualization.
If you really want people to learn, you would not give them access to this. This creates a major Achilles Heal in a person's chess. One that they will not realize its crippling effects until the Battle is being waged and they are taken doen before firing a real shot.
I absolutely 100% aggree! It will hurt OTB play. This feature should never have been!
You don't get an analysis board in live chess. You are allowed one, or many, in correspondence chess and from what I gather online chess at chess.com is supposed to be or at least mimic real correspondence chess. If you want to simulate OTB chess over the Internets, then play live chess; if you want to play correspondence chess online, play online chess.