I am the author and agreed with ALL of the posts that essentially fell into 2 buckets: 'for' or 'against' using cloud storage (outside of lds.org) to accelerate the work.
As noted by <russellhltn>, my answer can't be a clear 'yes' or 'no', it's a "depends". The decision, when I read all available guidance 2.5 years ago, falls to the Bishop. I doubt this guidance has been made anymore cut & dry. My Bishop authorized and encouraged our ward council's use of cloud storage and posting/tracking regular status in them, so long as I (clerk, at the time) did 3 things:
1. Used a single ward account to store cloud docs
2. Religiously pruned google doc 'share' access controls, as ward council members cycled out
3. For NRMP specifically, don't post dates in the Temple questions, a simple 'yes' or 'no' suffices
I was a clerk for 15 years, with the exception of google data mining, access to my ward's PII stored in the cloud was well controlled. No concerns were ever raised.
A thought - maybe one day the church will provision cloud storage for units and tie access control to our callings in http://www.lds.org/clerk
and take PII access control back. As a commercial example/corollary, my company has moved all their internal website development (highly sensitive data and intellectual property) and deployments to AWS containers. I am sure Amazon <https://aws.amazon.com/cloud> could make secure arrangements for the church, if my company was willing. This comment is not intended to ruffle any feathers, it just an idea. I am sure CHQ developer folks have considered or already use various AWS options for their projects.