Joe Abercrombie has posted an update to his blog in which he announces a likely release date for his new trilogy, along with the book titles.
According to him, the new trilogy:
has 7 point of view characters, 4 men and 3 women, as well as a host of walk-on extras, many of them well known to readers of the First Law, and features at least one duel to the death, three major pitched battles and an awful lot of hangings. It takes place mostly in the Union and the North, some 30 years or so after the end of the first trilogy as the world moves into a more industrial phase.
Joe Abercrombie also says he expects the first book to be published in September 2019, with yearly intervals between the sequels.
So far the books in the trilogy have the following titles:
A Little Hatred
The Trouble With Peace
The Beautiful Machine
You can read more about his update here: Progress Report June ’18 | Joe Abercrombie
I also asked Joe about his new trilogy in an interview I did with him a couple of years ago - so if you want to get an idea of his thinking you can read The Joe Abercrombie Interview here.