Distribution of schematics is 100% up to the company, as a previous poster quoted: they are that company's Intellectual Property.
In this day and age of offshore manufacturing and all the copying and cloning going on, I would suspect that acquiring schematics will only get more difficult in the future.
I work for two foreign manufacturers (dCS and Nagra) and am also McIntosh, Plinius and a few other brands authorized, and none allow me to provide schematics to end users or non-Authorized service providers.
