Documentation of changes to sound.m

Comparing sound.m in R2010a and R2013a shows that they have very few similarities. The work in R2010a is done by the PLAYSND mex file while the work in R2013a is done by an AUDIOPLAYER object. Comparing audioplayer.m in R2010a and R2013a shows that in R2013a audioplayer uses the ASYNC.IO object while in R2010a the auioplayer object is a java based object.

I thought I paid attention to the release notes for changes to the sound commands since they are important for what I do. Does anyone know if the cahnge was documented? Should TMW be publicly documenting changes like this (the input is identical and to a first order approximation the output is identical)?