It's both good and bad. Good because you have about 2 more hours than you normally would to explore HKDL. Bad because the only reason HKDL lengthens their hours is because they expect more people than normal during that particular day.
Disneyland Resort: Dec 2013
Walt Disney World: April 2015
Tokyo Disney Resort: April 2013, April 2014 Hong Kong Disneyland Resort: Oct-Nov 2006, March 2007, April 2008, April 2009, March 2010, Oct 2011, May 2012, Oct-Nov 2012, May 2013, June 2016...
1) Mystic Manor(HKDL)
2) Tower of Terror (TDS, DHS)
3) Soarin Over California (DCA)
4) Splash Mountain (TDL)
5) Haunted Mansion (MK, DL, TDL)