Many, many interesting thoughts throughout the comments here. Sadly, I think the slow decline is most likely as many have suggested. My deep interest is to have something significant happen within my lifetime to minimize the influence of the organization on existing JWs which includes me and my extended family.
Likely just wishful thinking and the reality is that any JW with no good way to escape is stuck until death or until the org starts to more significantly fade away - which could be decades.
A financial shock or a global virus that kills off significant population are the only two things I could come up with that could possibly happen sometime soon.