The giant worms of BOTFA are very unlikely to become part of the game. The Edain Team didn't like the very concept altogether. Regarding trolls themselves, I think there are some proposals in the previous posts that deal with armoured trolls, though I'm not completely sure about it; moreover, we don't have enough knowledge yet of the precise intentions (future intentions) of the developers in regards of BOTFA content. I can't unfortunately give you a definitive answer whether they want or not to explore more concerning trolls, beside the aspects which are already present in the faction. It's all speculation for now.
In my opinion, most of those concepts wouldn't fit at all in the game. The whole grotesque trait (farcical, at times) of the Hobbit trilogy is very prominent in their characterisation (as the infamous zombie trolls, for example). But I'm nonetheless very open-minded, though, towards possible scopes for additional inclusions from the third film; provided that they are really worthy of being considered, of course.