The main way I see it occuring is if you already have Greek Orthodox believers in lands that either were in areas that historically became Protestant or in areas where it could be likely reform could spread (i.e. a stronger spread of Greek culture and colonies, with or without the Byzantine Empire, in Italy, France, Spain, and Malta) or in lands ruled by outsiders who became Protestant (i.e. Finland). Finland here is actually interesting, not the least because the Swedish government actively persecuted Greek Orthodox believers who either fled to Russian Karelia, where it was safe to practice Orthodoxy, or took to remote areas where they could practice in secret. If Orthodox Finns and their church hierarchy were smart enough, they could have found ways to accommodate themselves to the Church of Sweden, though what you'd get instead would be a Protestant/Lutheran version of an Eastern Catholic (or Uniate) church, not a full-blown Reformation. In this case, Greek Orthodox doctrine, and more likely pre-Nikonian Russian Orthodox forms of worship and customs/traditions (i.e. what we now associate with the Old Believers), would remain but would adapt to a new environment even if in some cases in harmonizes with existing practice in the Orthodox world. Take the language of worship as an example - one of the things Protestants were big on were having the people know and understand what's going on in services, and this could be best done in the vernacular rather than in Latin - hence Luther's Bible and his hymnal, the KJV and the BCP, etc. Orthodoxy, too, has a tendency to adopting the local language wherever it goes, but since the liturgy had already been standardized ages ago, you could go into any Orthodox church and everything would still be familiar. You would know what to do and how to behave even if the language was unfamiliar. The same would be true here, even if the Finnish used in worship was heavily influenced by Church Slavonic. As for the doctrines and teachings - they would not change, but be reinterpreted to justify the new situation where Luther's Small Cathecism (among other founding documents of the Lutheran faith) now reign supreme. Yes, this would lead to the rest of the Orthodox world deeming the Finns as heretics and condemned as much as Cyril Lucaris was, but if that could stop Swedish persecution it could be a risk worth taking.