The term "responsible disclosure" may no longer have any meaning.
"Irresponsible disclosure" for the short term may be equivalent to "responsible disclosure" for the long term.
There must be some pretty dark stuff yet to be disclosed, and/or some pretty overt threats for those relatively fearless journalists to close ranks. The "Assange example" may have done its job perfectly.
Not just Assange, basically everyone involved except maybe Poitras took a hit. Appelbaum was driven out of his work with Tor (and from public life) after a smear campaign, Greenwald had to shift to alt media, and Snowden had to flee the country. Other journalists and editors “moved on” from their work with the papers.
Snowden did ask them not to get into any direct military secrets that were in the leaks, so that could explain some of the restraint.