Hi Anonymous,
For McKinsey, for experienced hires I am not aware of a global policy on that, and it would be even counter-productive if offices would not allowed to hire if they need a specific resource.
And that's probably a major difference for experienced hires - for university hires it doesn't matter that much, one equals the other more or less (sorry to be that general, but you get the point), for experienced hires however you take them because of a very specific skill-set.
And specific skill-sets are required all the time somewhere for something. Less than in the past and less systematic, but I know about new experienced hires over the last 2 months.
Hope that helps - if so, please be so kind and give it a thumbs-up with the green upvote button below!
Robert