Yes, Paul said separation shouldn’t be blocked. And then, usually overlooked, he said that the Christian “is no longer bound”. The context of being bound leads me to believe he was indicating that marriage could legitimately be ended as if it had never happened. Extraordinary passage. Remember his saying a wife was bound to her husband as long as he lives? That death breaks that bond. But here he uses the same word and says ‘no longer bound’.
We’re talking about abuse and/or desertion here, and he came down very hard on it.
JMHO.
Isn’t that passage re the case of an unbelieving spouse leaving/deserting a believer?
1 Corinthians 7:15 (New American Standard Bible (NASB))
15 Yet if the unbelieving one leaves, let him leave; the brother or the sister is not under bondage in such cases, but God has called us to peace.