On one hand, the message seems clear, though it isn't exactly an explicit way of announcing one's retirement.
However, reports have indicated that Lynch has been telling close friends he's retiring, and Seahawks GM John Schneider said on a radio show this offseason that all signs point to Lynch retiring.
So though it may not be an official announcement, it sure seems as though Beast Mode's days in the NFL are done, and he chose to say it during the NFL's biggest spectacle.