You're right. But the Snopes item which debunks the donation claim also includes
the following statement by legal counsel for the couple - looks like they do support BLM:
“The Black Lives Matters movement is here to stay, it is the right message, and it is about time,” said Albert S. Watkins, legal counsel for Mr. and Mrs. McCloskey. “The McCloskeys want to make sure no one thinks less of BLM, its message and the means it is employing to get its message out because of the actions of a few white individuals who tarnished a peaceful protest.’”