There are a couple things to note, or consider.
Whcih studio is working on it, it seems to me it could be the Australian studio trying to turn things around from a few of its poor games the last few years.
It will most likely use a the current total war engine, updated or regressed to support more melee, ranged.
Before gunpowered leaves us the greater part of human history.
Anything from 10000 BC to 1200 AD, but more likely 4000 BC to 1000 AD
still that is a large time frame.
Anything from the first settlements of cities to the Invasion of England in 1066 as the end point, or if you go east you could have anything from early chinese civilization to early Japanese and Korean, and add Mongols in there, the big problem with that is alot of the most famous periods from there involved gunpower. They could remake a classic, shogun/rome, I doubt medieval just because there have been two and the game is still quite popular.
Intern Game Scripter
Reverie World Studios