Rob got a letter from Citibank the other day canceling his CitiBusiness/AAdvantage Platinum Select World MasterCard. It was the exact same letter that I got in 2015, when Citi canceled my my Citi Hilton HHonors Visa card. (Note, this Hilton card is now obsolete anyway).
I called Citibank out of curiosity to find out their policy. Despite Rob paying the $95 fee, it was still inactive for too long. Oh well, but he did not use the card anyway and canceling a card should have a minimal effect on his credit score.