UPDATE 15/10/19: The island of Salamis has got its Pokémon back.
In a delighted post to the SilphRoad Pokémon reddit, island resident “Giannhsblazer” shared the good news:
“Last night a member of our community opened Pokémon Go and came across a huge surprise. After seven months of no spawns, the whole Saronic Gulf, including islands Salamina, Aegina, Agkistri and Poros, is once again full of them. Our combined efforts, gave us a great victory, and from last night, we are once again able to go out and hunt!
Source: Eurogamer The island where you can't play Pokémon Go