There are already enough confusion between games and books, only a few fans have really play and read everything, so add a new reality was really the worst idea.
Fortunately, the characters look different from the games, but they’re still hard to watch. The John we see is not a “Master CHief” to me.
Halo is a big universe who have hundreds story to tell, there was no utility to rewrite everything.
This is in fact not Halo. Took 9 years to get an alternate Halo universe story