If Battlefield 5 turns out to be World War 1 (1914-1918) , it occurred with good timing, because computer hardware is capable of handling the iron sights for detailed graphics. To shot a player at 440 yards with a bolt action rifle using iron sights in previous resolutions and monitors would not be practical. But with the increase in resolution and monitor size, now a days, more attention to detail is possible. Weapon’s optics of glass and electronics is a heaven send for low grade computer equipment, because you can zoom in and create a new screen that is separate from the current large field of view, even low graphic thermal imagery- not so with with iron sights, if you want to be realistic. What you see with regular eyes, is what you get when looking down the iron sights.
I, personally, would call it Battlefield 1914. With the following release dates of new battle maps:
BF1914 released 2016
BF1915 new battle maps (released: TBA)
BF1916 new battle maps (released: TBA)
BF1917 new battle maps (released: TBA)
BF1918 new battle maps (released: TBA)
Any and all previous maps would be a prerequisite of a new battle map.
Hint sheets would be in the form of watching https://www.youtube.com/user/TheGreatWar with each weeks release. A bit much for players, but so was the amount of soldiers fighting in one battle- by the hundreds of thousands! (see: Battle of Cer, 200,000 troops invade Serbia and are repelled, which became the Allied powers’ first battlefield victory!; Battle of Kolubara, 465,000 troops invade Serbia and are repelled again!)