Rod Fergusson, former lead developer at The Coalition, recently revealed the original plans for Gears 6 on IGN's Podcast Unlocked. The team had intended to move the story away from planet Sera and explore the rest of the solar system. This direction was hinted at by some of the space technology seen in Gears 5.
Interestingly, Fergusson mentioned that no final decision had been made regarding the fate of characters following the major choice players made at the end of Gears 5. The team was considering using player statistics to determine which character would survive for the sequel.
Here's a link to this Gears-specific podcast:
However, these plans have since changed. The Coalition is now working on "Gears of War: E-Day," a prequel set 14 years before the events of the original Gears of War. This new game will focus on the beginning of the Locust War, taking a different approach from the space exploration concept Fergusson had envisioned.
Despite this shift in direction, The Coalition has stated they are "not retreating" from the modern Gears saga, suggesting that elements of Fergusson's original vision might still be explored in future installments.