Can you give a link, to the post to which you refer?
Should I wait to upgrade?

http://www.chess.com/forum/view/community/upcoming-changes-to-chesscom-memberships
If you don't have a use for the free gold membership that you would currently be paying for with a platinum upgrade, I say you wait and save the extra money.

Platinum will be "much cheaper" but not include the tee shirt. I don't care about giving a gold membership to anyone. If the price reduction is more than $19.99, then it might make sense to wait.
I'm thinking of upgrading my membership and giving the free Chess.com tee shirt to myself as a Christmas present. But there was a post recently indicating changes in the higher memberships. Should I wait before going Platinum?