Further evidence that natural selection is true and macro-evolution is false.
Right, and wrong.
It is support for natural selection, since the beak size trait being selected for no longer matters, due to the introduction of new food sources (apparently).
This study says nothing about "macro-evolution". These birds were all members of the same species, which had been diverging, but now are not.
There are several (I think 14?) other species on the islands which HAVE diverged into separate species from a common ancestor.
Just go on believing that as it makes you feel good -- regardless of the logical error you are making.