For many years it has been scholarly dogma that Esrog did not grow in Eretz Yisrael in Bilbical times and, therefore, the identification of "goodly fruit" with Ethrog was post-biblical. Now comes evidence that Esrog was grown in Judea during the First Temple period, here.
See here on Ethrog in Josephus.
This reminds me of the "camel" controversy. It was similarly claimed for many years that the story of Abraham and his camels msut be an anachronism because camels were not yet domesticated in the Bronze Age. This also turned out to be incorrect. See also here.
The lesson is that we must approach scholary dogmas with a good measure of scepticism.