"Medieval" by definition refers to the Middle Ages: "The period in European history between antiquity and the Renaissance, often dated from a.d. 476 to 1453." [source] We can squabble over just how wide a swath, geographically, this refers to, but generally speaking this does not include East Asia, South and Central Africa, Australia, or the Americas.
It goes both farther than this and not as far.
SMA does not only mean the setting is only medieval; it is also specifically the warrior class nobility of the european medieval period. Whatever you do, your character is a
knight. He is not a ninja, or a tribal leader, or a siberian shaman.
There are things that happened in Europe between 700 and 1300 that I would not consider SMA. The Sami people, for example, existed in that time and place, but their society was far removed from the european feudal nobility framework. I would object to having a realm based on Sami traditions, because I would have a hard time recognizing the characters as knights.
However, there are things that did not specifically exist in that time period but can be very well adapted to the BM context. Gender equality is such an example: it did not exist anywhere in the form we see in BM, but it was fitted to the SMA requirements and female characters are RPed as knights. The atmosphere remains medieval, even if the details are not.
