Nothing is permanent in real world if there is something that exists then it will also end some days and same goes with bitcoin too, and no one can predict what will exactly happen in future.
Yes all possibilities can happen, bitcoin might be able to disappear in my opinion. If bitcoin left behind and the price has no value bitcoin will definitely be left behind and will slowly disappear. But if bitcoin grow and increase surely will continue to exist. It all depends on the circumstances bitcoin from time to time, and no one can be sure exactly.