*banging pots and pans* Wonder Woman isn't Greek! Wonder Woman shouldn't be Greek! Wonder Woman isn't Greek-coded! Themyscira isn't a Greek island! The Amazons in Ancient Greek writings were a highly exoticized melange of several (largely Anatolian) cultures!
Themyscira, the real Themyscira, was not a Greek island but it was a real Greek city in Pontus, in Anatolia. It just had this foundational myth that it was originally built by the Amazons. The Amazons were not Greek and they were exoticised, but saying there is no Greek-coding at all is a bit of a stretch. The most famous Amazons all bear Greek names, Hippolyta (Diana's mother), Penthesilea, Antiope, and there is also connection to the Greek gods, since they are products of the Greek myths.
The myths for the Amazons were inspired by real-life female warriors (not living in exclusive societies, but rather in more gender egalitarian societies) who are speculated to have been Scythian, though that is a hugely broad term, spanning from Northeast Europe to Caucasus to Iran and Central Asia.
