This no doubt increases the demand for Bitcoin and thereby making it more valuable.
I will like to know what will happen to Bitcoin when it looses this position to fiat or other cryptocurrency?
Hmm... Pretty interesting thought you have there pal. To be honest, the only thing that I can see happening to bitcoins when exchanges ever decided to also pair any other alcoin out there to fiat, is a big problem for bitcoins and a huge decrease in its price. Although I do not think that it will cease from existence, I think it will really balance out the whole crypto world. But this can be avoided if the developers find a way to make a use for bitcoins that will really take interests from the masses other than the purposes it serves today.