I think they will do whatever it takes to keep the corporation going.
As the donation base recedes, dying off of the old timers, more descendants leaving and few new converts, they will look to business/real estate investments to keep it alive. They have plenty of those and have very savvy business people actually running the corporation.
As a religion, they will make it easier for people to be counted on the rosters. The message won't change much, it doesn't have to. They've had basically the same message for decades with just tweaks for the lasting the decades, lol. They could go mainstream but for what purpose? People could go anywhere for that and not have to deal with the baggage of the WT. .02