Would anyone treat a Satmar this same way they are treating Chabad here
That is completely and utterly irelevant.
We are not questioning Chabad because they look different, or are classified as chassidim. This is not some sort of racism, so to speak. We are questioning their beliefs, and to some extent, actions, which are not at all shared by Satmar.
The Satmar Rov was not very fond of Chabad, and this was well before the messianism was so blatant.
The Satmar Rov was more of a rosh kehillah than a rebbe anyhow, and certainly never declared himself leader of the entire generation, so the issue I’d succession isn’t comparable either.