Right now, they can join a cult if they want. But soon that option won't be available anymore. The time for experimenting with cults will have passed. Cults hurt people. God's not going to allow people to hurt people anymore at a certain point. He's allowed them to try cults and it doesn't work. (He already knew it wouldn't work from the beginning, but He allowed them to try anyway, because they wanted to, but He put a time limit on it.) The precedent's been set. Soon no more cults. Ever. Cult-free life, woo-woo. Happy day. Hallelujah. He'll undo the damage from them and anyone in the future whoever says "hey, let's do the cult thing!" will be reminded - "ah, no, let's not."
We already see the evil from the cult-lifestyle, but many of the JWs do not see it yet. They will see it shortly, whether they want to or not - Jehovah is exposing all of it, from the foundation to the roof. It's going to be completely torn down and exposed. When the WTBT$ hierarchy is dismantled, the rank-and-file will see the false doctrines for what they are, and they won't cling to them anymore. They'll be embarrassed they ever believed in them.
It will happen fast.