I agree with you that many newly converted JWs do not have a clear picture of shunning.
…are you sure elders discuss the details of the shunning policy with prospective baptisimal candidates?
I think much depends on elders individually. The ‘Organized to Accomplish Our Ministry’ (p198 in my Russian copy) has a question about ‘what the congregation does when someone is sinning but is not repentant’ and it lists 1 Corinthians 5:9-13 which says ‘do not associate…’ and also Titus 3:10 which says ‘reject him…’. Now, who those verses apply to is another question, and the elders may or may not chose to emphasise this point, imo.
I personally had a very stressful experience with that. When I already considered my disengagement and knew shunning was not scriptural I had to discuss this portion with a baptismal candidate. I tried to downplay and moderate the Society’s viewpoint but the elder who was with me decided that it was a question that needed additional attention. So he asked the candidate: Say, you meet someone (df or da person) on the street – will you greet him or her? The sister hesitated evidently thinking what to say: the answer the elder expected from her, or her genuine understanding. He then continued: Suppose he (apostate) approaches you, looking at you, perhaps smiling or waving his hand – will you greet him? More pause and tension and the sister says, stammering, y-y-yes, I’d greet him. I applauded inside.
The elder continues: Well, how can you say you’d greet him? What does the Bible say? Predictably, the sister quotes 2rd John, still hesitating if she can justifiably apply it to everyone who left. ‘So would you greet him if the Bible says ‘do not say a greeting to him’? The sister bursts in tears and says – no, she wouldn’t. I sit there, eyes to the floor, numb. I was a MS and being there with an elder at a baptismal discussion was certainly a ‘grand privilege for me from Jehovah’.
Since I disassociated, I met that sister on the street. She didn’t look at me and hurried away. Guess that’s part of my pay for my cowardice to discuss the matter with her while still in the org and another reason why I personally found the system that has such near total control over their members repelling.