The MRFF, which seems to be above board and its existence widely known by military personnel, is quoted directly in the article as having received the complaints as described. An article in The Guardian [1] tells the same story, but adds another MRFF quote: “Anytime Israel or the US is involved in the Middle East, we get this stuff about Christian nationalists who’ve taken over our government, and certainly our US military,” Mikey Weinstein, MRFF’s president, who is an air force veteran, told the Guardian.
“Military members are not really able to stand up for themselves, because your military superior is not your shift manager at Starbucks,”
This doesn't really confirm or debunk, but it's surely a solid nudge towards confirmation.
-- Edited to add: Another commentator, who takes the story with a pinch of salt, casts aspersions at the MRFF. [2] The penultimate paragraph should really be far higher up.
In the interest of balance, here is what McKinsey has to say about social responsibility in its "about us" section of its corporate website: Our purpose as a firm is to help create positive, enduring change in the world.