https://youtu.be/J1K-z2HuVZ8

The Koei Tecmo released the video about celebrating the Dynasty Warriors Series' 20th Anniversary. It started from Dynasty Warriors 2 in 2000 to the current Dynasty Warriors 9 in 2018. The first Dynasty Warriors is not included since it's the fighting game like Tekken, Dead or Alive or Street Fighter.

　① Dynasty Warriors 2 (2000)

　② Dynasty Warriors 3 (2001)
　　・Xtreme Legends (2003)

　③ Dynasty Warriors 4 (2003)
　　・Xtreme Legends (2003)
　　・Empires (2004)

　④ Dynasty Warriors 5 (2005)
　　・Xtreme Legends (2005)
　　・Empires (2006)

　⑤ Dynasty Warriors 6 (2007)
　　・Empires (2009)

　⑥ Dynasty Warriors 7 (2011)
　　・Xtreme Legends (2011)
　　・Empires (2013)

　⑦ Dynasty Warriors 8 (2013)
　　・Xtreme Legends (2013)
　　・Empires (2014)

　⑧ Dynasty Warriors 9 (2018)

Since the Xtreme Legends or Empires expansion is not coming for the Dynasty Warriors 9, looks like the Koei Tecmo decides to move forward and it's the possibility that the Dynasty Warriors 10 will be created, but, for now, there is no announcement for it just yet.