Indeed. If you reject that "the room as a whole" speaks Chinese, you reject functionalism. If you think philosophical zombies are conceivable, this is also a rejection of functionalism. Ultimately the acceptance or rejection of functionalism is (as far as I can tell) only a matter of dogma, and these two arguments serve to find out which dogma you (implicitly) subscribe to.

Personally I place the rejection of functionalism on basically the same level as the acceptance of dualism. I don't know what precisely has happened to make most serious researchers reject dualism, but perhaps non-functionalism will run the same course.