The father of Gears of War left the franchise after Gears of War 3.
Cliff Bleszinski is known as the father of Gears of War, but he left the series after Gears of War 3 happened. In other words, Gears of War 4 and Gears 5 were made without him, and the same is true about the upcoming Gears of War 6 as well.
It is no surprise, that Cliff Bleszinski had ideas about how to treat Gears of War after the initial trilogy. He has now published a concept photo on Twitter about a new kind of Locust, that he hoped to continue the threat on planet Sera.
Unfortunately we will never know, how it all would have turned out.