On 25th April 2020, J.K. Rowling revealed on Twitter that she was working on the sixth novel in the series. She tweeted that she was writing a scene with Strike sat in a crowded London bar in 2015.
Funny you should ask. I'm with him right now in a crowded London bar. But we're also in 2015. https://t.co/6gzc1rleCY— J.K. Rowling (@jk_rowling) April 25, 2020
The fifth novel, Troubled Blood, will be set late 2013, possibly early 2014, which means if the sixth book is set in 2015, it will take place approximately a whole year after the events in book five.