Yes that my biggest pet peeve. Even if one is shunned because he’s doing something very wrong in the congregation and then was kicked out, no where does it say that if this one stops and is repentant he is to be still shunned for another year or two until the elders decided to stop it.
Something else to consider and maybe inwrong on this but I believe that 2 Corinthians was written as a type of apology for the things written in 1 Corinthians. So Paul had a change of heart.