IMHO it would be a smart move for the devs to release a free DLC which adds the new building modules (as well as some items like the recyclotron) to the base game for everyone who owns Below Zero. Shouldn't be a lot of work for them and would likely be an incentive for quite a few people who just own the base game to buy the new one as well. Also, we all know that modders will likely find a way to do it themselves sooner or later (by making a script that extracts and moves the relevant data from BZ to the base game as releasing the files directly would be illegal)
