Never attribute to malice that which can be adequately explained by stupidity.As I suspected, the opt-out e-mail blast was a mistake, accidentally sent to the wider audience instead of the smaller one. It seems that there was a bad call by an inexperienced staffer, combined with a lack of process and control.
Admittedly, it was something of a tempest in a teapot; part of the reason why this perceived violation was so noticeable is that, to date, WashingtonPost.com has been a trusted source (at least, when it comes to self-marketing). For such a rookie mistake to appear was... jarring.
Additionally, as I had surmised, my blog entry is currently the #1 search result for the term post livewire. So I got that going for me.