Microsoft actually delayed the game for a year to polish it more. Per the Gamesradar article, "Starfield had a much earlier release date before Xbox told Bethesda to take its time":
"Truth be told, when the acquisition closed this game had a significantly earlier ship date than where we're actually launching in," Spencer stated, clarifying that he was referring to the November 2022 release date. Spencer added that he then "sat down with Todd and the team," and explained that they wanted to give this team "the time" to finish Starfield