Is the one who rules that a person who judges by other than what Allah revealed is a disbeliever considered one of the Khawarij?

Question:
The Honorable Shaykh, may Allah grant you success, says: There is no doubt that warning against extremism in declaring people disbelievers is a necessary matter and is part of the core of calling people to Allah. But, Honorable Shaykh, some people go beyond this matter by labeling scholars and those engaged in the creed of the Salaf and refuting opponents as Khawarij and takfiris, because they hold that the act of one who resorts to man-made laws is disbelief, while they affirm the rest of the matters of belief. Many of these people who throw the label of Khawarij at well-known scholars cite some fatwas issued by the great scholars of this era warning against extremism in takfir, and they apply them to these people. Is there a word to be said on this matter?

Answer:
I understood only one thing from this question, which is that he says that those who rule that the one who judges by other than what Allah revealed is a disbeliever are Khawarij. The issue of judging by other than what Allah revealed has a detailed explanation, as the scholars have mentioned.
It may be a disbelief that expels one from the religion, it may be a minor disbelief that does not expel one from the religion, and it may be a rewarded act if one exerted effort, sought the truth, and judged by other than what Allah revealed through ijtihad, missing the truth, and judging by other than what Allah revealed not out of intent, but out of ijtihad where he exerted effort and erred in it.
The Messenger (peace and blessings be upon him) says one. So judging by other than what Allah revealed has a detailed explanation; it is not all major disbelief, nor is it all minor disbelief, but rather it is necessary to distinguish and apply the rulings to the specific cases.