i think same could be said for all introverted types, but its not the vision that other types are trying to preserve. for Fi doms, its the personal feeling evaluations. for Ti doms, its the logical reasoning and for Si doms its their subjective facts. however i do think that Pi doms have stronger need to preserve their perceptions, because those perceptions are not grounded by reason, thus they are harder to influence by others. Ni doms might be even harder to influence than Si doms, because the perceptions cover much larger area than Si doms, so it would require much more convincing from others to have an influence to their vision. if you add the protective nature that they have on their visions, devaluation of things that others(who go against their vision) say, it might be nearly impossible to have any profound influence to their vision.
with certain things, it might be equally hard to convince an Si dom to change their perceptions about something, since the perception is highly subjective and is essentially about what something evokes in them. also the thing with Si is that, it is about facts, but its not about objective facts(whether a chair exists or not), but about what they associate to a chair, so in order to change this, you would need to prove that they are mentally ill, that the chair doesent exist at all or that their perception isnt really a fact, but a product of for example archaic feeling or thinking, which just makes it seem like a fact to them, because the "fact" isnt really a fact, but it just seems like a fact because their perception is clouded by feeling, thinking or intuitions, which they dont recognize as such(due to their unconscious influence on perception), but simply see as a fact that has been perceived.
introverted thinking types can be more easily influence simply by offering a model that makes more logical sense than their previous thought. and introverted feeling can be influenced, by not saying that what they feel is illogical, but by explaining how it is morally wrong and showing how it conflicts with some of their other feeling based evaluations about right or wrong.