Relying on Google Translate to read a French interview that has answers interpreted from Japanese...it's not an ideal situation
Yu doesn't even say he couldn't fit 50% of his ideas into Shenmue III. He said he couldn't fit 50% of his ideas into other games and the interviewer asked if that was also the case with Shenmue III...to which he replies maybe, but not really -- basically. It was like he gently disagreed with the interviewer.
The NPC comment is particularly hard to parse. It seems like he's partly talking about NPC relationships to one another (e.g. backstory). He mentions the small-town feel of the original game being different to Shenmue III, like it made more sense for NPCs to talk to you in that game than it does in III. I'll accept that reasoning! Especially since it sounds like the "important" NPCs have been fleshed out more, which could be what the "Here, we have emphasized elsewhere" comment is referring to.