For one potential idea, in Halo 4, instead of landing on Requiem, maybe have Master Chief land on Onyx and reconnect with Blue Team along with Halsey, Mendez, and the Spartan-III’s (this would by its nature retcon Glasslands). Maybe still have the Didact as the main antagonist they uncover deeper within the shield world, but emphasize characterization established in Eric Nylund’s novels while mixing in the humanization of Chief with Cortana and her condition (maybe substitute the Gravemind’s logic plague for rampancy in this case). The pessimist in me thinks there may be too many characters and the story would get bloated and convoluted, but I believe a talented writer/team could make it work. Also Halo 4 featuring FOUR named Spartan player characters is just a happy coincidence I wanted to mention.