Of course dropping shunning would change the organisation dramatically - for the better. The crazier ideas would need to be dropped because they would be exposed to scrutiny. That’s not a threat, it benefits everyone, including the leaders who are probably embarrassed by some of these teachings themselves.
But I think you’re wrong to say it would take a long time to change the shunning culture. Shunning is simply not natural and many JWs would drop it instantly if sanctioned to do so. On the other hand many JWs would continue to have strained family relations inside and outside the religion - as is human nature. They just wouldn’t have the “cover” of disfellowshipping to explain their nasty behaviour any more. Plus there’s also the issue of people who have been shunned for years or decades. Would they forgive JW relatives who now resume contact? That’s a choice individuals would need to make in these complicated situations.