Ryk writes:

it simply tells you that if
you increase the temperature by adding heat, then either the volume or
the pressure will increase.

No variable in the equation expresses heat. It does not tell you
*anything* about heat or its relationship to the variables it does express.
It does *presume* that Q = 0. If Q happens to be non-zero, then the
equation still holds while the values change, but the equation tells you
*nothing* about an unexpressed Q relating to T, any more than it tells you
there are unexpressed forces changing V, or a leak in the container
changing n, or radioactive decay changing n, or any other physical
principle you can imagine.

An equation must express a quantity to "say" (predict) anything about it.

An equation may be affected by unexpressed quantities, but the equation
literally does not say anything about unexpressed quantities.