I don't believe it was a miscommunication. Even if it was a company as important as Docker inc, mentioning DELETING containers requires some care and should raise some flags at any serious communications department.

This is not just the wrong date for a convention in the newsletter. What impact does it have on the ecosystem they've built? Some really serious projects use Docker and even if they have their own repositories can they be sure the software they rely on can keep publishing containers?

Even at the tiny startups I've worked on I'm asked to proofread any technical stuff they want to publish, I assume Docker does too.