(Read the link. This is all about who's the real employer in indirect-employment situations.)
[1] https://www.morganlewis.com/pubs/2024/03/nlrb-blocked-from-i...
It also doesn't fix the problem where a number of contractors sue you even if they might be wrong. It could very easily be a class action lawsuit like the one that cost Microsoft a lot of money. They could use those rules as a start and then throw a few other things together such that Google thinks it might have a problem in court and wants to settle rather than risk getting sued by every single contractor.
The NLRB makes nearly all its law via adjudication, not rules. The aggressive interpretation of joint employer is what is causing companies to put up walls between employees and contractors so they don’t get swept up by the NLRB.