I think its already too big to get destroyed by another altcoin honestly.
there is always a chance for everything.
even there is a chance for you to get hit with a rocket when you go out of the house today.
but happing or not is the more important question here.
and since the chance is near zero, it will never happen.
Bitcoin is well developed now and already established a good support from the community. I see if bitcoin will end, most people in the community will not be interested now in other alts so just a few will transfer to other coin and maybe eventually will stopped too as time passes by.
It's really hard to imagine that bitcoin may be end soon despite of the strong status today.