There is a reason for that. Greece should have never been admitted to the EU in the first place and now that the ECB is squeezing every last Euro’d drachma out of them, the Greeks are looking for a new set of friends. The Russians are a lot more palatable to even the more conservative Greeks, now that Eastern Orthodox clerics are not getting thrown into jail.
You don’t understand the EU, then. It’s an empire, and they would have no problem “admitting” Greece if they could squeeze whatever they felt like squeezing out of them. The EU has no legitimacy.