The concierge etc are standard features of MasterCard "World" products. I believe the merchant transaction fees are higher on World and World Elite cards than on Platinum, Gold, or Standard Mastercard. It sounds as if Citi may be converting cards to increase revenue.
I agree. World, Visa Signature, and World Elite seem to be just ploys to increase fees. I do no think that the transaction networks care about income or spend. They just want to issue everyone a higher-end card so that they can make additional trxn revenue. On the consumer-side, it provides an illusion of affluence and induces additional spending.