“A case of politics determining what should be solely a religious determination.”
That is correct, although for the opposite reasons you think. Nobody with any knowledge about Rabbi Weiss, even those who oppose his innovations, thinks that he has said or done anything that would put him outside the halachic bounds of what constitutes someone with kosher eidut. It is his enemies in the RCA, who won’t even come forward and identify themselves, who think that current politics should decide halachah, and snookered the Chief Rabbinate into going along with them.