The small issue with reviving Joy Silk is that the Supreme Court is the one that abandoned it.

As such, the NLRB, despite what they may want, doesn't actually have the authority to revive it.

They are just hoping the facts in this case are egregious enough that a court lets it slide.

That may or may not happen - the NLRB traditionally does not have the greatest success in court, even in days where unions were much more supported in the US than they are now.

One outcome in fact is that the courts decide to gut the power of the NLRB