4A Games, the studio behind Metro Exodus, have advertised a number of job listings explicitly for a "new IP". While 4A appear to be hiring a large number of staff in general, there are six roles that are labelled as for a new IP: three design roles, and three artist roles.
There isn't much that can be divined about any future game from the job descriptions, though the listing for a senior technical artist goes to some interesting places, tonally: "Never use the word 'impossible'." "Doing R&D means digging your own path ignoring doubts." Many of the other listings on 4A's site seem to avoid the 'games wizard/ninja/jedi' tendencies that pop up in passion-based industries, emphasising the importance of taking on critical feedback and being receptive to other people's ideas, which makes this particular one stand out.
Metro Exodus, which was released in 2019 and saw an enhanced edition release back in May, is an incredibly visually impressive game—if demanding on your PC. It makes sense that they'd plan to continue in kind for future projects. Details from other listings ask that applicants are experienced "with 1st person or 3rd person action titles" and have a "passion for FPS games", so it doesn't look like they plan to move too far away from the mechanics they're familiar with.
In his review of Metro Exodus, Andy Kelly found the expansive game to be "full of surprises and stunning scenery", even if he was disappointed that his primary engagement with the world was with shooting at it.
A series of job listings is not an announcement though: we will likely have to wait a while before 4A have anything official to say.