Evolve dev Turtle Rock Studios say that the game has been specifically built to accommodate DLC.
DLC talk is part of the inevitable pre (and post) launch marketting spiel for pretty much every triple A title these days, and while Evolve dev Turtle Rock Studios didn't drop any specifics, it did state that the game was being specifically built to accommodate a whole boatload of DLC.
"You know, in Left 4 Dead we could make new environments, but we really didn't have a structure there to make new characters or zombie types, so we were pretty limited on what we could do, DLC-wise," explained Turtle Rock co-founder Chris Ashton. "But with Evolve... we made these modular pieces--the way the whole game fits together means we can make new maps, new environment types, new wildlife, new monsters and hunters, and all of that stuff just plugs into the game."
While I'm sure many of you are groaning at the prospect of $5.99 weapon packs, Ashton stresses that the community will help shape what these DLCs are, and how they will be priced "We're definitely looking to see how the community reacts... It's designed to have a long life--hopefully that works and we get to try a bunch of crazy things with the community after release," he said. "As long as people are into it and the DLC does reasonably well, then we'd like to keep making more."
He did, however, add that "At the end of the day, it's a business and it has to make sense, but we believe that we've built a game that does support that really well--more so than any game ever before."
Left 4 Dead and Left 4 Dead 2 were Turtle Rock's previous games, and they featured a pretty substantial amount of DLC that was released (for the PC at least) absolutely free of charge. However, this was due to Turtle Rock being partnered with Valve, and Valve enforcing its philosophy of free DLC for its games.
Now that Turtle Rock is independent, and especially judging from the way Ashton is talking, I doubt Evolve will be quite as generous with its DLC. It's also worth noting that all Evolve DLC will have timed exclusivity on the Xbox One.