No. First of all, no human remains have ever been found at the Titanic. It is not likely that any ever will be found because there is nothing about the conditions of the site nor the conditions of the human body that would resist decomposition in that area.
Actual leather items such as satchels, shoes, and wallets have been found preserved, because the tannic acids used in processing the leather made them reisstant to microorganisms. This is likely the source of this rumor.
However, tea tannins and tannic acid are NOT the same thing. Tannic acid, used in creating leather, is derived from oak leaves, not tea. The two are chemically different and drinking tea or coffee won’t preserve your internal organs.
A web search indicates that it is a common misconception that tea tannins are the same type used in processing leather.
Cervus – On the topic of Tanic acid … Hey AMY!