Yes because...
*SPOILERS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!*
At the end it showed the MC and cortana, who will not be in the marathon series because her 7 years ran out, floating towards the planet. I have not played the game but I heard that marathon starts out with a ship crashing on a planet and a cyborg getting out or something.
Also, there were 2 marathon games, and in the legendary edition johnson said...
"I'll see you in the next trilogy, I'm in it, right? RIGHT?" So that leaves me to conclude that they are going to complete the marathon trilogy, and in the long run continue the Halo story line, by making a third marathon game. Of course, it wouldn't quite fit in with the marathon games graphically or technology.