If they went bankrupt they will have been very foolish with their funds...but if they did, they may not even tell the bros. They have vast assets which they can use as collateral to borrow money and if that does not work out they can sell off property to reduce or pay off debts. The key thing for them is to keep the faithful in the fold and paying money into the coffers but even here many will suspect what would be going on and pull away.
The trend in religious membership is to be “spiritual”. This late 20th century phenomenon is part of the personal and self regarding approach to faith which disregards authoritarian dogma. It is in evidence here on this site where believers report that they go along to the meetings but do not accept the Borg mentality and regulations... and it probably is part of the reason why WTBTS funds are dropping.
The beliefs could well remain if the org collapses. Already the doctrines of JWs are evident outside of the WTBTS, especially in Africa, (BK is JWism on steroids) they will splinter more rapidly if the money fails and the centre does not hold so the fear and threats from the anxious GB would increase, losing many believers in the process and the remaining flock would have to adopt a siege mentality... very unhealthy!
Well that’s one scenario!