According to the IGN articles, Shinbori says it's a new engine they're using.
Not to worry, DOA6 will still have the hype stages :)
Source: http://www.ign.com/articles/2018/06/08/e3-2018-dead-or-alive-6-first-hands-on-can-team-ninja-balance-familiar-and-fresh
As much as I would love to see Lei, Anna and Julia revealed at E3, I'm not going to keep my hopes up. I'm betting those 8 DLC files are probably just additional customization items.