In The Name of the Tsar is the title of September's Battlefield 1 [official site] expansion, which producer Andrew Gulotta says will bring “a revolution" to the game. It's bringing eight new maps, the Hussar cavalry, the 1st Russian Women's Battalion of Death, and new forms of player progression to help with specialisation. It's coming September and you can see a little glimpse below.
The Eastern Front could have a very different feel to the existing Battlefield 1 maps, but it's hard to say what it'll bring to the game until we have a proper play. Other upcoming changes include night maps, taking place across a "massive network of trenches", and that is an enticing prospect.