What the case is actually testing
Three legal questions are in play. Each one has implications beyond this case.
Can a plaintiff establish disparate impact when the decision tool is a model? Under US employment law, disparate impact claims do not require proof of intent. A plaintiff needs to show that a neutral practice produced a statistically significant adverse effect on a protected group. If the algorithm selected a disproportionate share of women, older workers, or employees from a specific ethnic background, that is sufficient to shift the burden. Models are not exempt from this standard. The lawsuit argues they should not be.
Does the employer retain liability when the decision is model-assisted? Meta's likely defense is that human managers made the final calls. The plaintiffs will argue the model constrained those decisions in practice, that a manager looking at a ranked list effectively ratified the algorithm. Courts have not ruled definitively on where that line sits. This case may draw it.
What counts as adequate documentation of an automated decision? The EU's AI Act requires that high-risk AI systems used in employment include specific logging and explainability. The US has no equivalent federal standard yet. But a California court ordering Meta to produce documentation would create a de facto evidentiary expectation that other plaintiffs in future cases could point to.