I understand the prevailing idea of fantasy has become nearly entwined with the medieval. And I’m not going to patronize anyone with the “Nostalgia Argument”. If this is or isn’t why you want it to go back to the medieval style, that’s fine. But if not, what other reason do you want Final Fantasy to return to a medieval style?
Beowulf or the first tales of King Arthur are fantasy. To us, they’re in the “medieval” period, but these stories take place in that time of writing. Kingdoms, castles, and dungeons were pretty much what we think of. The Bible deals with fantasy (meaning magical/supernatural elements as the main plot element, theme, or setting). And even when biblical prophets saw the future it was usually their near future. I guess they were just purist par excellence…
So, the stories of Beowulf, King Arthur and the Bible were fantasies based on reality. Final Fantasy XV, for example, is a fantasy for our time. I have come to appreciate the concept of fantasy more once I realized the many different facets.
I don’t oppose another medieval setting in a Final Fantasy, but I wouldn’t limit myself to this idea of fantasy. FFVII, FFVIII, FFX and even FFXIII were all aspects of fantasies in this respect. I (personally) don’t think Final Fantasy has to go back to anything 😀
So why do you want Final Fantasy to return to a medieval style?