Disco - as I understand it, the court limited the issues to the 5-page brief by each of the parties {eg, each party got 5 pages}.
From there, if you read rule 9019-5 about a mediator, all materials provided to them are confidential. We will never know what was provided and what was not.
So certainly, if a given party filed something under seal, and it was relevant, then they could point it out {and provide a copy} to the mediator.
What the court also specifically said, when ordering the 5-page summaries, was that she was not expecting nor requiring the mediator to go back through 3 years of over 9000 filings and catch up on all of it.
It's up to the parties in mediation to bring forth what they feel is relevant, and whatever materials are relevant.
...Catz