Indeed, it would be very traumatic for many JWs.
I kind of hope that a better religion might emerge. One that still opposes war, uses God's name, and preaches a paradise earth, but one that doesn't shun people or discourage education, free discussion, and trying to make the world a better place where possible.
Maybe if they closed the religion down as gradually as possible that would be the kindest way to do it. Like continue the steps they've been taking:
1. Stop the book study
2. Reduce the literature near to zero
3. Cancel the midweek meeting
4. Reduce the WT to a series of questions for open discssiom
5. Stop recording ministry time or having organised ministry meetings
6. Say any person who gives wise advice is a "faithful slave"
7. Consign 1914 to history
8. Be kind to former JWs instead of shunning them
After implementing those changes it would hardly matter if they closed their doors in the end or whether they continue as a positive community. Either way it would be less traumatic for all involved if they did it gradually.