: Chief was last seen at the end of the CE flying in a spaceship away from
: Halo. Presumably he flew home.

: Johnson hangs a lampshade on the fact that he's still alive. The script
: literally makes a joke about it.

: "Chief jumped from the ship" is literally the first scene of the
: game. It's not mysterious at all.

: The Arbiter flew back to Earth with Johnson and Keyes. It can be easily
: assumed based on what is shown.

: I honestly don't follow you. Jackals looking slightly different is a much
: smaller change than "Chief has a family -- and humanity has
: additional saviors -- that no one ever mentioned".

: I've never been thrown by a gap between the Halo games like I was between
: Halo 3 and Halo 4, and Halo 4 and Halo 5.

Agreed on all points. None of these missing links seem as substantial as the sudden appearance not just of other Spartan IIs, but Spartan IIs that the Chief considers family. Maybe we'll get some kind of exposition that lends some weight or significance to their presence, but I wouldn't bet on it.