The blog author additonally emailed support with a lengthy overview of the changes and reponse from the rep and received the reply that v6 of their product has always been a cloud subscription only offering, which according to the author's experience was not the case.

The primary contention of the blog post and the tl;dr is v6 of the product allowed for a 'local' vault until a particular build and AgileBits isn't being open about this change, which the author feels is some slippery slope to other, hypothetical compromises.