Regarding the external expert for inclusive process you are looking for, maybe this article is of help:
https://hbr.org/2016/12/how-employees-shaped-strategy-at-the-new-york-public...
What did the New York Public Library do that the Foundation doesn't already do in their ordinary course of action? "The three core teams were given a month to present to senior leaders options for their experiments, and the capabilities needed to try them." That sounds like business as usual at the WMF.
I have specific questions about this week's strategy announcement; in particular:
https://www.youtube.com/watch?v=m5R5PgBk5b8&t=42m25s
"A general layer of meaning that sits right below the Vision" is the Mission. I am certain that the Foundation doesn't want to dictate a Movement strategy at variance with or supplanting the Mission. So why not declare that the Mission already is the de facto Strategic Direction and save the time and money to re-do it for implementing the recommendations of previous strategy work?
Seriously: these strategic directions from 10 years ago still need work:
https://meta.wikimedia.org/wiki/Special_projects_committee/strategic_goals#a...
And what happened to the Recommendations from the past couple years' strategy work?
https://meta.wikimedia.org/wiki/Strategy/Wikimedia_Foundation/2016/Recommend...
Can we use the ratio of FTE hours working on new strategy projects and those working on prior strategic goals and recommendations as a measurable key performance indicator in a way that encourages accomplishing prior recommendations and developing new ones in a way that doesn't lead to discarding work?