A ceiling mount tends to hang plumb because the weight is more or less centered under the pipe. An upside down application will be the reverse. The TV will tend to want to fall off to the side because it's above the mounting point. Your challenge is to stabilize things so that doesn't happen.
A good answer is easier with a clear question giving the make and model of everything. "The biggest problem in communication is the illusion that it has taken place." -- G. “Bernie” Shaw