I'd be interested to know if you can link to a single example of someone insisting that they be referred to using a neopronoun (and not accepting e.g. they). Here, for example, is a discussion of neopronouns on r/nonbinary: https://www.reddit.com/r/NonBinary/comments/k7hegi/can_someo... I don't see anyone getting canceled for expressing a degree of skepticism about neopronouns.
I also think you're being slightly disingenuous in talking about 'accepting people's identity at face value' as if it was being proposed as an absolutely rigid rule. No rule of social interaction is completely rigid or without exception. If you really have a reason to think that someone is being dishonest or disingenuous about their gender identity then you don't necessarily have to go along with whatever they tell you. But if you are not inherently unwilling to believe trans people in general, how often is that scenario going to come up?