Considering Denmark is also one of the richest countries on earth we can neither expect other countries to a) detect such a mutation early and b) handle the issue promptly.

So I think it's somewhat likely that we'll see mutations emerge all over the world.

Whether this vaccine works depends on how early we get most people vaccinated. It may only be a short term patch, which we will see once it's rolled out, you can't really predict the long term without any measurements.