The linked comment was posted a day ago by what appears to be an account used for speaking officially about GrapheneOS.
So, like, you could go ask.
Nah. The guy who -presumably- has all the relevant information in his head can be reached by writing an HN comment. The proposed question is directly relevant to the comment you'd be replying to.
Regardless of how the guy replies... with a sensible story, bullshit, or silence, everyone saves a ton of effort by asking him.
Seems stupid to go redo a whole bunch of research when the primary source of the claims in question is figuratively sitting right next to you and obviously open for conversation, doesn't it?