Demanding that people repeat and affirm the slogan, therefore, seems risks demanding they endorse the organizations.
I don’t know Dean Yuracko’s inner thoughts. But I suspect she has fairly progressive views given the nature of her research (gender equity) and that she believes “black lives matter” as a literal factual statement. But being pressured to repeat that statement, as the slogan, and the name of an organization with some fairly radical ideas, is a differently thing entirely. In America, we don’t go around forcing people to express solidarity with a political movement, no matter how meritorious the movement.
What I dispute is the proposition that any reasonable person assumes such an endorsement also constitutes an endorsement of the Marxist beliefs of "BLM, Inc.", a name I'm introducing to capture the organization you're referring to.
I agree that BLM, Inc. is so hospitable to radical socialism that we might as well refer to it as a radical socialist organization.
I strongly disagree that such tendencies also apply to the slogan "Black Lives Matter"; BLM, Inc. has lost its hold on the slogan, and no longer owns it. That's what happens when a slogan succeeds so wildly it's on every bumper sticker and lawn in Oak Park.
(I think this is more or less what the libertarian Foundation for Economic Education has to say about BLM as well).
Yes, they created the slogan and hashtag in 2012 and the Foundation in 2013, and the Movement for Black Lives was founded in 2014. (Much of this is express in the excerpts you cite.) The organizations did not exist until well after the slogan was popularized, and the various organizations within the movement (even the big two) mentioned are not without disputes over both policy recommendations and priority between them; the slogan isn’t a sales technique for the programs of one organization or the other, the organizations are working to try to establish how to make the slogan concrete.