Each animator uses different tricks. normally no model has morphs to remove the clothes, the most you can find is the classic alpha morph.
If you are looking for a more natural and realistic way to remove clothes, the only way is for you to invent a way because there is nothing "standardized" for that.
each animator uses the different tricks that he has learned over time or "imitating" other videos using them for inspiration

I assume that you are referring to this model "ht tps://3d. nicovideo.jp/works/td41754"
If so, then no, it doesn't have a morph for the clothes, you have to make them yourself, you are gonna need this in order to do that "ht tps://www. deviantart .com/inochi-pm/art/PmxEditor-vr-0254f-English-Version-v2-0-766313588"