Thus, The main problem of writers is to make narrative which will be interesting both newfags and oldfags.
There were no such problem in D:OS because its hystory barely connected with previous games. By the way, It seems like Dragon commander almost has no such connection.
But they intend to place D:OS 2 in centre of original trilogy.
E.g., during Kickstarter company, I've read about some "Divine order" in every second update and can't understand what is that?
Eeehh, not really. When BG came around it wasn't filled with detailed descriptions of what the Sword Coast is or what an Ogre is. They need to make the narrative in such a way as to pay homage to the lore, but also to be easily taken in by new people. Remember the betrayal that was Ultima IX? We have to avoid that. The Divine Order is The Evil Church(tm) basically. Though whether it's evil or not is yet to be revealed, but it all points that way.