Segment Next reports that Grim Dawn 2 is being talked about but is only in the planning stages.

Marczewski also reminded that Crate Entertainment had only a couple of full-time employees back in 2009 when development of Grim Dawn originally started. There are around a dozen staffers working right now, an expansion that materialized right after Grim Dawn was released in 2016.

In other words, even if Grim Dawn 2 goes into full development straight away, a release can possibly not be expected anytime soon. Crate Entertainment will likely take a few years before making any announcements or reveals for the potential sequel.

[...]

Crate Entertainment's Arthur Bruno has been interviewed at Gamsutra, explaining the plans to buy Iron Lore's Black Legion IP had to be shelved and they instead proceeded with a smaller, "dark" fantasy, PC-only, downloadable action/RPG that has yet to be revealed in full:

It was time again to adapt. With Black Legion's future highly in doubt, Crate turned to its roots -- the PC-based action RPG, Bruno and Crate's comfort zone. With just five core people, a few contractors, and even some volunteers, Crate licensed Iron Lore's Titan Quest engine and toolset from the defunct studio's co-founders, and began work on a new project.

"In this case, Crate Entertainment’s small size works to its advantage," Bruno explained. "We don’t need a big publishing deal to sustain us and PC, more so now than ever, presents a lot of opportunity for smaller titles. Our ability to work out a very reasonable deal for the Iron Lore Engine and toolset was another huge enabler. So we put together a project that we could begin developing without reliance on outside funding."