"Two months" is boilerplate language for the worst case of when you will see it on your credit card statement. It's legacy language from pre-Internet days when people couldn't watch their charges post.

Hypothetical worst case example:

Today's date 3/28
AA processes refund: 4/3
Credit card statement gets issued: 4/4
AA refund posts to credit card: 4/5
Next credit card statement issued: 5/4
Credit cart statement shows up in the mail with AA refund on it: 5/12

Everybody uses the "two months" or "two billing cycles" language, but it's no longer realistic.