I think it's been pretty conclusively shown that tech companies have no problem ignoring or bending their own content policies when it's convenient. they could just argue that union busting doesn't count as "political advertising." maybe they're responding to the online blowback against their Do It Without Dues campaign, as well as the general momentum and public support behind the unionization drive. They'll definitely still try to stymie it by other means, but I think they're losing the propaganda front and they know it. either that or there's some potential regulatory consequence that I'm not aware of, but idk much about what tools the NLRB actually employs against businesses.