Technically there is no details defined in NATO treaty about reasons and procedures for expulsion of a member state. They have left it wide open and can interpret it anyway they want. Basically they say in case of "material breach of the treaty" the membership can be revoked. And "material breach of the treaty" can mean anything like war crimes committed by Turkey in Syria.
P.S. At least 16 countries in Europe surpassed double digits inflation so far.
I am not sure about this, but my guess is that Turkey is the second strongest member of NATO, after the United States. On paper, the United Kingdom and France are stronger since they have nuclear weapons. But in terms of military strength and capability, I guess Turkey is ahead of them. Other NATO members such as Germany, Italy and Spain are far behind. I don't think that a majority of the NATO members would like to lose Turkey from the alliance. If the choice is going to be between Sweden and Turkey, then I am sure that it is going to be the latter.