The info maybe a little outdated for some things but most things are are afaik still in the game.

here are the countdown to open beta previews for


formations / Unit Animation
https://forums.totalwar.org/vb/showthread.php?t=53591

Senatus Populusque Romanus (previewing most of the roman factional units)
https://forums.totalwar.org/vb/showthread.php?t=53849