Quote Originally Posted by Buffalobiian
Come to think of it, it's not the first time they've stopped animating seals. Raikiri used to require one too. Now they get used on the fly.
Kishimoto changed his mind about how Raikiri works when he introduced the Rasengan.

I always assumed this was generally the Itachi effect. Suddenly everybody became so bad ass they do them faster than we can see.