Halo Infinite was originally due to launch for the holiday season last year, but due to a ton of backlash over the lacklustre visuals of the game seen in trailers so far, the team decided to delay the game with, as it stands, Holiday of this year being the target instead.
As for when it'll release exactly still remains unknown, but according to Xbox's Phil Spencer, the team "feels good" about a release this fall. "We know kind of our range in the 3-4 week range,” he said, while chatting on the Dropped Frames podcast. “We don't have the exact day. There are some other things with some other game timing that we're trying to look at. We'll have better clarity over the summer, but this isn't a months thing this is just down to a few weeks."
So it seems, barring any more controversy, that fall is the date, but there's a reluctance to commit right now as Spencer says he is trying to avoid leading people to further disappointment. "Instead of picking this date and having to move it by a week, which at this point would feel like a fail—we don't want to do that—let's wait until we're really solid on what the date is."
For me, it comes when it comes, and more time to polish it and improve the experience is fine in my book. There's likely a lot to release around the holiday season, too, so picking a date this far out seems like it would be a bad move in any case.