This year's Metro Exodus was very well received, even getting two DLC episodes, one coming in the next few months and the other set for early 2020. Any way you look at it, the Metro series is still chugging along, and looks to be for a long time. According to the author of the Metro book series, Dmitry Glukhovsky, the "series will be continued".

In a post on the author's Instagram, he confirmed that he is currently working on the story for the next installment in the franchise. The game will not be based on a book by Glukhovsky, but will instead be an original story written for the game.

Metro 2033 was an experience that surprised us not only with its polish, but with its world building. The fairly linear experience was expanded in its sequel, Metro: Last Light, improved its gunplay and A.I. while also opening up the world to more than just the metro. Metro Exodus blew the doors completely off, taking the player and a ragtag group of survivors across Russia. With their horizons broadened, where Artyom and Anna go next remains to be seen; we will probably have to wait a while before we learn any more about the upcoming title.

[Source: Dmitry Glukhovsky via Gamespot]