You don't cancel a game nearing the final year of its development based on rumors. Come on man, think.
Jason Schreier said that sentiment from within bungie itself around Marathon was not great 220 employees who worked on the game got made redundant in the summer. An internal playtest at the end of 2023 gave mostly negative feedback according to Schreier the game has received multiple delays and isn't a guarantee to make a release date in 2025.