Will he go down as a big part in the history of Jiu-Jitsu?
If I follow history correctly:
1) jiu-jitsu was an art that Samaria used for fighting purposes that involved ground fighting but also strikes, swords and other weapons etc.
2) Times changed and jiu-jitsu almost died out. A few ryu's were still in tact but they were teaching to common citizens and challenge matches were the competitions. I gather it was like vale tudo but I could be wrong.
3) Kano wanted to revive the art and he created a system that took from different ryu's and he created a sport to eliminate the "violence" if you will and make it more sportive. He also changed the name to Judo in an attempt to get away from the "thug like" reputation that jiu-jitsu practioners has attached to them. Kano's Judo went thru different stages where ground fighting was a focus and then ultimately standing became more of the focus because Kano thought it to be more exciting. Kano spread his art around the world and Judo became very popular.
4) Judo/Jiu-Jitsu hits Brazil. The ground fighting aspect was much more the focus in Brazil. Helio became famous for his guard in different competitions. Schools opened up that focused mainly on the ground aspects of jiu-jitsu. The name jiu-jitsu was the preferred name and there became a sport called jiu-jitsu and perception was Judo is more stand up while Jiu-jitsu is more ground.
Now are we living in a time where jiu-jitsu is being changed once again and Danaher is influencing the way jiu-jitsu is played. He seems to be taking jiu-jitsu to another level by adding leg locks and takedowns to the sport.
Will he go down in history as changing jiu-jitsu and be included in the history 100 years from now?
One more thought, Helio also cemented his place in history when Royce dominated the early UFC's.
To solidify your place in history I think you need to be recognized as being the man that changed something. Kano changed the image and took out a lot of the killing techniques and created a sport. Helio changed the sport to be more about ground and he also was involved in changing America's perception of what fighting is. Up until the UFC America was thinking fighting was standing and striking. And now Danaher seems to be changing jiu-jitsu, nogi has became more popular, leg locks are better than ever, and if Danaher is able to succeed in his attempt to make stand-up a bigger aspect of jiu-jitsu sport then he might go down in history as a major influence. What do you think?