Sorry for the confusion; let me clarify.

If I agreed to upgrade to an AMEX Platinum, AMEX would ALSO give me an AMEX AEROGOLD PLATINUM at no additional charge.

I was not interested so I didn't question, but I thought they were giving me access to the lounge and free companion ticket, etc with the AEROGOLD, and the continued ability to put points with all their partners with the other card.