Quoted:

There's more than just understanding the "benefits" of free floating. Free floating a barrel is a method to reduce inconsistent forces acting on the barrel to increase shot-to-shot consistency. For example, a shooter may apply a different amount of downward force onto his bipod between two different shots, or he may take one shot from the bipod and the next shot from a crouched or kneeling position. These changes impart different forces on the barrel, and if it's not free floated, it WILL change the point of impact. Even a small force on the barrel can deflect it enough to miss your target. If you have a free floated barrel, try pulling on the barrel some time, you'll see the barrel move relative to the handguard/rail.

So, free floated applies directly to whatever part of the stock or handguard that you would hold or rest on a bag or bipod and the barrel. You do not put any weight or force on the gas tube or gas block, whatever force (probably from gravity) that acts on those parts is exactly (in theory) the same for the first shot as it is for the hundredth shot.  So, since it they play no part in how you hold your rifle, they are not considered when it comes to determining what "is" and "is not" free floated.