The opinion piece written by NATO Secretary General Jens Stoltenberg is the official confirmation that migrants rescued at sea by NATO assets will be repatriated to Turkey: no mention of whether Turkey is a safe place of return for individual migrants and refugees.
Repeating that the operations will be conducted in accordance with international law will not make it so. The international law referred to seems to include only the principle of territorial sovereignty. International human rights law is not mentioned, and the fact that migrants have rights not acknowledged.
How will migrants be able to demonstrate that return to Turkey is the wrong decision in their individual case? If the migrants are picked up in Greek waters, this will really amount to a collective expulsion of the kind prohibited by the European Convention on Human Rights. The involvement of NATO seems to be expressly designed to prevent the European Court of exercising jurisdiction on such operations.