What happens when a Jehovah’s Witness who has been disfellowshipped returns to attending the meetings again?
If it's the same congregation that they previously attended then, yes, the congregation will remember who they are and so continue to treat them as dead or invisible.
One of the identifying marks a cult is that it uses shame and humiliation to control members, to keep them from leaving and manipulating those who escaped into coming back.
A disfellowshipped person is never allowed to quietly leave with dignity. Instead they’re actually announced from the platform to the entire congregation. Members understand that they’re now not allowed to acknowledge the person - even if its their own mother, child or sibling.
Just like in totalitarian dictatorships where a person who falls out of grace with Stalin or Kim Jong Un is displayed in front of everyone in a show trial.
Trying to attend another congregation where nobody knows you won't work either. Because the cult actually keeps files on its members, and if you turn up to a Kingdom Hall and claim to be a member the elders request your previous congregation to send them your file.
Your file contains information about you, how many hours you’ve spent knocking on doors, the “sins” you’ve committed, how many show trials (known a “judicial committee”) you’ve been subjected to and much more.
You know, like a cult?