In-between Meta’s “to show that we have competition, we would like to show company Foo’s documents on X, Y and Z” and this subpoena is a judge who decides on whether those documents would help them reach a decision in this case, and whether it’s reasonable to ask Foo to do that work.

Also, the data you provide goes to the court, not (directly) to Meta.

I also think you can ask the court to keep (parts of) the data from the public record. That would require an argument as to why making it public would harm you.