The reason (at the moment) is a couple of upcoming martial arts sets from Shout Factory that hold some promise:
Martial Arts Movie Marathon (The Skyhawk, The Manchu Boxer, The Dragon Tamers & The Association)
Release date: May 20, 2014
This one is the more intriguing of the two for me because two of the titles, DRAGON TAMERS and THE ASSOCIATION were released in Hong Kong by Joy Sales on DVDs and VCDs with no English subtitles (I believe DRAGON TAMERS was only on VCD, no less). While neither Amazon's nor Shout's listings indicated whether this set will include all four films in the original language with English subs, Shout's other set gives me hope:
Martial Arts Double Feature (Lady Whirlwind / Hapkido)
Release date: April 22, 2014
This pairing (on a single disc) DOES include Mandarin tracks and English subs, apparently, as well as English dub tracks. Judging by the not-super-cheap pre-order prices on both of these sets, I'm hoping Shout went to the added expense of including original audio and subs on the Marathon set as well.
I'm curious if Shout has licensed other early Golden Harvest films previously released by Joy Sales. Those discs were alright, and I managed to get most of them, but there were oversights here and there, and now that they're going out of print, it would be nice to have a domestic alternative.