When all those algorithms become public parts of the stdlib, they surely will confuse a lot of people who simply want to bring a list of objects into the right order. I personally welcome that kind of confusion, as it opens a door to learn something new - but still, I think there is a better way than changing the stdlib:
import HeapSort
//…
sort(myArray) // will perform heapsort; details up for debate
This would not only keep the surface of Swift smaller, but also be more convenient for those with special sorting needs: I don't think there are many situations where you need different algorithms (beyond benchmarks to compare them).