I don't think you'll see a building system in FH2 for a few reasons;
1) There's a lot of work/ testing involved with implementing something that changes gameplay so drastically. The devs aren't focusing on revolutionizing gameplay that much right now.
2) A building system like Squad/ PR doesn't really mesh well with FH2's style of play. FH2 isn't geared towards strategy in the same sense as those games. Gameplay is much faster than PR where the slower pace allows people to strategize and take the time to create spawn points with their team before going into battle.