Strange, because I feel like Lucas intentionally didn't put as much focus on Yoda's lightsaber prowess in the Sidious duel for precisely this reason. He gave us a good little reprise of what we saw in Attack of the Clones so we wouldn't feel cheated, but he pulls back the perspective on it so the emphasis is more on the larger spectacle of these two titans of the Force dueling in the middle of the Senate chamber as the podium rises from the floor. He then dispenses with both of their lightsabers so they can fight more directly with their Force powers. He knew we were no longer seeing Yoda use a lightsaber for the first time, so he couldn't just rely on that to maintain interest. He didn't try to do the exact same thing.