The episode underscores the folly of the U.S. law enforcement demand that tech companies install backdoors into their devices and services.
the WSJ comments. This time the leak is an unintentional backdoor the NSA used to get onto devices. The NSA used the Vulnerabilities Equities Process to determine that ETERNALBLUE is burnt and informed Microsoft, which then promptly generated an urgent critical patch, which did not make it out to systems in the field fast enough.
There is little difference according to the WSJ between flaws being used as government backdoors, and intentional government backdoors, which may be detected and abused, or leaked. So this whole Wannacry(pt) thing is a very good example of what will happen with Government mandated backdoors in systems.