Yes. "Cis" is just a description, like "straight" or "white." Calling someone "cis" is not an insult, but some conservatives take it as such. The common phrase they echo is "I'm not cis, I'm normal." They're trying to denormalize trans people by making an inoffensive and common descriptor an insult. The same people sometimes have a problem with being called straight by queer people because they see themselves not as straight, but normal, and anything different is abnormal. In reality, "gay," "straight," "trans," and "cis" are no more abnormal descriptors than calling someone "black," "white," "American," or "tall." It's all just "othering" those they perceive as political opponents.