In Mission Impossible 5 Benji (aka SImon Pegg) plays Halo 5 for a bit (think the Avengers guy playing Space Invaders).
It would seem that MI5 is set in the future then, by a few months, or alternatively the past with the beta (though I am sure Benji has the skills to hack into playing Halo any-time he wants!).
The product placement goes on for quite a bit, and the Halo 5 logo gets a big closeup too.