IT was 4 until about a month or so ago. Now it is relaxed - more around 2.5 - 3L, and you can count the water in your coffe/tea/shakes/soups.
There are mixed opinions about this. It is an official announcement from LL.
Many are still drinking 4 because we got used to it. So, aim for 2.5 litres and any more you are comfortable with or thirsty for is how I approach it most days. I make a point of having 4 litres a day though about 3 days a week. Don't ask me why! lol
Hope that helps. Main thing is to keep well and fully hydrated - drink to thirst, etc. being sure to get your minimum in.