Is this all applicable to z/OS?These questions were entered live during the webinar so in that context "all this" probably refers to the content of the presentation and for that the answer is yes. Things like CHLAUTH rules and authorizing cluster queues work the same on distributed and z/OS. In general, the differences in WMQ features between the platforms are disappearing.
Of course, z/OS has many differences in things that are external to WMQ. For instance, managing keys with RACF is completely different than managing them with GSKit. Also, z/OS uses RACF rules and so the part of the webinar where I discuss SET AUTHREC rules does not apply. Tom Schneider wrote a great article
Comparing WebSphere MQ security on distributed platforms and z/OS which describes the major differences. Although it was written for v7.0, most of the differences are external to WMQ and still apply.