I see very very less chance of it happening. Because bitcoin is the pioneer in crypto currency world. The market cap is already huge which shows the interest of the people in bitcoin. So it is hard to replace bitcoin.
But on the other hand I won't say that it is impossible. You may have some other crypto currency which may grow up to bitcoin's level in future but probably that currency won't have the power to replace it. It is just that people will start enjoying the fruits of that currency as well. That will be only good for the crypto currency world only.
The bitcoin is the first big coin and it is supported by many people and organisation. It will become even bigger.
Yeah it can become more bigger just like this year many happening about bitcoin and more price increase will happen and more investors will come because the adoption is increasing and i think we need more adoption about bitcoin.. here in my country bitcoin is adopted in some company like coins ph.. they are adding more merchant to exchange our bitcoin that we can shop online products and service i already both some dmain using their service and i think they can add more in the future..