This sounds plausible to me. But you think that it is easier that somehow some birds survived the submersion of the island?
It's well known that flightless animals, such as moose, can and do migrate significant distances and colonize islands. They do it by swimming. Could flightless birds do the same? Quite possibly.
It seems reasonable, to me, that a population of these flightless birds would colonize nearby land. What sounds more incredible is that they would then up, leave, and find their way home, thousands of years later -- all without leaving a trace. Perhaps this leads to an interesting follow-up study: are there geological records, or populations, of flightless rails on neighboring islands or nearby land masses?
The atol in question was surveyed in the early 1900s. The rails were there. There has never been a time -- that we know of -- when the rails weren't there.
There are also dozens of other types of birds, giant non-marine tortoises, flying squirrels, bats, and a huge assortment of reptiles.
The only 'fact' that underpins this story is the assumption that "all life on the island went extinct" at some point AFTER some particular fossil of the rail was found.
There is no basis for this 'fact'. It's absurd. There is also no explanation regarding where the other non-marine animals on the island came from after this speculated 'extinction' event.
To be clear, there is no story here UNLESS one assumes the entire atol was submerged at some time AFTER the fossilization event.
Rails exist there today. The fossil record has rails. There has never been a time when there weren't rails that we know of. And there is no solid evidence that all life went extinct on the atol, and a large amount of evidence that there was no extinction event.
> To be clear, there is no story here UNLESS one assumes the entire atol was submerged at some time AFTER the fossilization event.
Figure 3 of the original article suggests exactly that. Rather than call people idiots and heaping scorn for a "lack of critical thinking", find a counter-argument. Like, perhaps the atoll was taller, and a few meters' erosion could make the difference. But I'm not a geologist, so that's just an armchair guess.
Disclosure - I am not, consequently I have no vested interest in either explanation (the article's considered, moderate, science-based proposal, or your knee jerk dismissal).
I am confident the authors of the article considered the possibility that the animal(s) never actually went extinct, though the basis for their conclusions seem sound. The journals would be full of wild claims if things not seen for a few decades were deemed to be miraculously rediscovered after each hiatus.
That the fossil bones (of the originals) and the skeletal structure (of the new) are similar, but not identical - let alone the submerged island problem - speaks against your claim that they're the same.