From Frank Diranna:

2.5.1 Requirements

Modern Vintage motorcycles must use a frame and engine case 10 years old or older, as determined by manufacturer’s model year. For 2011, the model year must be 2001 or prior.

Change to:

2.5.1 Requirements

Modern Vintage motorcycles must use a frame and engine case for a model started in production 10 years or older, as determined by manufacturer's model year.

For example for 2013, a yamaha 2003 R6 model started 10 years ago is legal, also should be legal are the 2004 and 2005, as they are the same model with no updates that are not currently banned from updating the 2003 model to.