Darwin's finches show only microevolution

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Claim

Charles Darwin's finches show only microevolution. In a long-term study, the changes were small and oscillated back and forth. They show no evidence for macroevolution.

Studies done on the alternations of beak sizes that correlate to periods of wetness versus drought were meant to demonstrate microevolution, not macroevolution, in the first place.
This disparity in beak sizes is brought about by disruptive evolution, and, contrary to the above claim, will often exist on the macroevolutionary scale: it can lead to sympatric speciation by means of behaviourally-caused reproductive isolation of populations. As an example, alternative beak sizes in the Medium Ground finch, Geospiza fortis, affect the mating call, and so provide a behavioural barrier to gene flow.
The fact that there are several distinct species of finches on the Galapagos Islands, along with several of these species split up into distinct subspecies, all descended from a single, ancestral species of finch from the South American mainland strongly refutes this claim.
That some populations of finches have been demonstrated to modify the size of their beaks in direct relation to the size of seeds produced during alternating periods of wet periods and droughts does not, in any way falsify macroevolution.
How does the beak oscillation of Darwin's finches negate the observed appearances of Oenothera gigas, Culex molestans, and Rhagoletis mendax Ã— zephyria within the last 300 years?
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Denying the Antecedent (because Darwin's finches do not show macroevolution is not evidence against marcroevolution)
Straw Man (Darwin's finches were not necessarily intended to demonstrate macroevolution)
Suppressed Evidence (of speciation, and other examples of macroevolution)
Moving Goalpost Syndrome (definition of macroevolution keeps changing)
Fallacy of Soundness (erroneous assumption that beak size can't lead to macroevolution)