I'm pretty sure 'actual environments and dynamic AI' were what Halo was about.
Before Microsoft bought Bungie, yes! In the first game, you could actually see a bit of these leftovers in the level design of Level 3
Silent Cartographer, which was the best level in the game. The whole second half of the game was horrible and I don't even want to start to talk about the sequels. BUT THIS WON'T TURN INTO A HALO DISCUSSION, we have plenty of topics for that.
Actual enviroments goes much further than that. Remember SystemShock1 or Thief 2? Levels were actual places, not levels or a series of corridors with one open door each. Interstellar Marines wants to go to the next level by adding all furniture, water tubes, electrical systems and so on to these places. You can damage the power supply for example which will do much more than just turn off the lights.
I am really curious who this new investor is. They dropped some hints that it's actually sb from the community.
Hell, I would have done it myself if I had the economic power, a game like this could reinvent the genre on it's own and sell huge numbers if you promote it right and choose the right release date (summer

)