Oh no you don't. We've been through this before. Now with Porsche clearly fine with dipping into the Formula One driver pool for their third car, the silly season rumors around F1 drivers and the World Endurance Championship are bound to get even sillier.
Here's a theory that I'm just going to throw out there: Felipe Massa is from Brazil. Interlagos, where the 6 Hours of Sao Paulo is being held this weekend, is also in Brazil. Motorsports is also a tiny, tiny world where folks who do one type of racing tend to have friends in other kinds of racing.
Back away from the tin-foil hats. Williams probably isn't going to pull a Force India and let Massa out of their sights for long enough to go run a couple WEC races on F1's off weekends.
So, wild theory: he's just out to enjoy a lovely race weekend at his home venue.