Superboy, you make an excellent point: Reinvention is not just the story of JWs but of Christianity in general. Christianity may promulgate an absorbing tale of love and redemption but it specializes first and foremost in flexibility and tenacity. Ask any salesperson about effective methods: Flexibility and tenacity will be among the top tips.
Besides, there's a palpable difference between re-grouping to reduce attrition (the organization's primary focus, I'd say) and reinvention to generate a surge in growth.
Sadly, too, some dogs have had their day: No matter how cute and adorable, some beliefs are products of another time and place. They age very badly; I'd suggest the JWs 19th-Century fixation with end-times is well pased its use-by date - at least in terms of a viably popular movement.
Sure, there will likely always be an organization in one form or another - but it will be obscured by newer, smarter, more modern religious fascinations. The organization will survive - but it will never re-capture the sizzling hold it had on rapid growth and expansion seen some decades ago. THat which is top-heavy falls over sooner or later.