If your agenda is to see the end of the WTBTS, it won't come in your lifetime. If you want to make a change in your life by leaving, then go ahead and do so. Forget about the WT crumbling; it won't happen any time soon. Assuming the Dateline programme ever aired, it will not touch 99.9% of Witnesses in any fundamental way; in fact the congregations will very likely receive orders to put members on guard not to watch it - and most will obey.
pc