So, new speculation: who are the sharp players in the Wizengamot who are drawing up lists on Harry?

They're not Lucius or Dumbledore, both of whom already know a great deal, and the former is too enraged to really be thinking beyond 'why did Voldemort just sacrifice all his wealth for a "friend"?'

I would be a little shocked if Umbridge was meant; she's so moronic in canon that even a MoR brain-upgrade still leaves her dim and bureaucratic, and she certainly doesn't match. And the powerful-wizard background is much more of a 'male' thing, to boot.

Mad-eye Moody could be expected to be making a list, but as far as I can tell he's not present and is remarkable enough that if he was, he would be mentioned. He's also apparently busy watching over & poisoning graves. In one chapter, Bones mentions he just retired, so he wouldn't be there in an Auror capacity. EDIT: Aftermath would seem to imply Moody was not there, because Harry didn't recognize the Moody in the Pensieve memory at all, despite him being quite striking.

Madam Bones seems too much on Dumbledore and Harry's side to be so suspicious, and not 'new' in any plot-meaningful sense. She's otherwise a decent enough candidate.

Bartemius Crouch is a candidate: as a Ministry head of Magical Law Enforcement he might be at a Wizengamot meeting (the Crouch family is highly respected and pure-blood and related to the House of Black, but the HP Wikia doesn't list them as nobles), is old, and canon seems to imply he was powerful & competent in Dark-hunting (speaking hundreds of languages) and about as suspicious as Mad-Eye, so he meets all criterion. And he's been mentioned in MoR before as alive & active, and more importantly, still part of the Phoenix network.

Does he appear in the chapter? Well, there is a nameless male wizard who takes Harry's threats very seriously, who apparently can command the Aurors:

A strange male voice spoke from somewhere far away, "Be sure that the girl is taken directly to Azkaban, and put under extra guard."

I'd say there's a good chance that that is Crouch, and he is also one of the 'certain few' in the epilogue.