This was revealed by the head of 343 Industries Bonnie Ross who spoke on an episode of IGN’s Unfiltered show. According to Ross, she explained why the next installment of Halo took longer than before, where the developer chose to skip its more traditional three-year development cycle in favor of developing a brand new engine, Slipspace, for the upcoming game.
According to Ross, “The Halo engine is a very technical, engineering-focused engine. It’s super hard for creatives to work in. It’s super hard for a lot of creatives to work in, at one time. We did a ton of work, on Halo 4, on the engine, to get it to look… I think it looked amazing for being on the last generation on the last year of the platform.”
Ross also went on to describe Halo Infinite as being a “spiritual reboot”, but unfortunately beyond that, she remained mum on what we might be able to expect. However with the game now confirmed to make an appearance at E3 2019, we suppose we won’t have to wait much longer to find out.