yes it may happen but i think bitcoin has reached to a level where it is difficult for any other cryptocurrency to replace it or reached to its level because it takes a huge time to evolve and bitcoin takes almost 10 year to reached this level. in other words we can say that it is the mother of all cryptocurrency.......
I agree with you, before being replaced by bitcoin need to go through the same path that it and it's not so simple and fast. If it happens it will be a ban on the bitcoin everywhere, then of course it will be replaced by another cryptocurrency.