So this is not some grieving random person from crowd - Chas is a person whose libraries and contributions I value tremendously and he certainly made LOTS of contributions to clojure OSS landscape for free and out of his good will as well. So ultimately this feels like your parents are arguing (which is never a good thing) - you like them both and you just want the arguing to stop and you just want everybody to live together in harmony. But here you go, Chas has moved away from clojure now. And I have to say I am very sorry to see him go.
"Never, ever, ever give a talk about a library or other code publicly unless it's in a public repo prior to the talk. Period. (Exceptions to this might be things like case studies and such.) Doing otherwise is surely irritating to talk attendees, but it's even more disrespectful towards organizers, as their acceptance of your talk may have been implicitly preconditioned on the attendees being able to benefit from the code/library/project in question."
Is the expectation now that when you talk about something it is necessarily going to be open source? (And from there the expectations grow and grow...)
I don’t see a problem with talks that show code (to support whatever the talk is about) without giving it away.
Read the whole thing in context. He's apologizing for jumping the gun - for giving a talk about a library he intended to release, before it was ready. The implication is that it was probably a "hey try this library!" kind of talk, that has little value to the audience without the code, so he's saying he should have waited.
Giving talks about closed code that will never be released is separate from all that, and clearly not what he's talking about. Hence the exception, "case studies and such".