Going straight from Dean Lister to the DDS ignores so many talented grapplers, such as Joao Assis and Davi Ramos, that used leg locks to get wins on big stages. Not to mention Palhares heel hooking his way through ADCC 2011 and the UFC around the same time. The 50/50 game had an entire system around it as well. The DDS was much more of an evolution as opposed to a revolution.

Leg locks have been part of no gi grappling for a long time. You can go back and watch the Cobrihna/Rafa Mendes match at ADCC 2009 and see them engage in leg lock battles. The theory of dragging a more skilled player into the leg lock game to take advantage of his lack of understanding in that area was articulated by Ryan Hall in the late 2000's and was what he used to beat black belts while he was still a purple or brown. Even in IBJJF competitions, toe holds and knee bars have been used forever. Cobrihna subbed Bruno Frazato with a toe hold to win the world's in 2008, I believe. Cavaca was a monster with straight footlocks and used one to win Worlds in 2010, submitting Cyborg in the finals.

The DDS made some great improvements to the leg lock game, but so did a lot of other people.