@EzekielRaiden @Corinnguard
I dont have the book Heroes of Faerun yet. But based on what others have said, it supplies backgrounds (with unique mechanics) to represent a unique local culture. Example, the initiates of the Dragon Cult have a special feat. This distinctive cultural institution trains secrecy and tracking skills.
This is exactly the kind of local cultural options that I expect an official setting to supply, and apparently Heroes of Faerun does this.
Even when using multicultural backgrounds from core rules, these are opportunities for the DM and player to negotiate ways to make them culturally specific by grounding them within a certain place and group of people. These narrative (non mechanical) rules supply unique culturally specific resources. Even a DM that is less confident about mechanically tweaking a background should be doing things like granting an advantage to History skill checks when referring to a characters own cultural background.