I see no reason that you not pursue this matter if you haven't been playing games with your account. Nothing in this thread or my own personal experience (I have slowly reduced my 400K plus account to just over 200K through flight usage) leads me to believe that a call to inquire about a missing 10K point would result in cancellation of your card.
I am not a fan of Citi TY and have told them so many times (usually resulting in bonus points. However, in Citi's defense, they are in the business to make money and despite the opinion of many posters they are not stupid.. The indiscriminate closing of accounts for no justifiable reason is no way to make money.
I doubt that the number accounts closed is more than I minute fraction of the total TY cards out there.
Basically there is no reason for non-abusers to run scared.