Thanks for the pointer to Society of Science, George. I noticed that Society of Science is the organization that partnered with Westinghouse in 1942 to establish STS, and that Society of Science had existed for about 20 years by the time STS was established--meaning that by then it was presumably a well established organization committed to advancing the interests of the scientific community by the time STS was established.
So if George's proposal is that some big corporate sponsor (I don't know if he has a particular sponsor in mind) will take on a role equivalent to Westinghouse, which org will take on a role similar to Society of Science? Most of my comments on here can be reduced to a single discussion point: in this project we are going to need a strong advocate for the mathematical community similar to the role that Society of Science has played for STS.
I don't know if anyone has any organization in mind to play this role. Early in the Aftermath of "The Book", George, Gabi and István write: "...the Committee on High School Contest agrees to lend its expertise and leadership initially in overseeing the content and philosophy of said journal. In particular, during the first two or three years, the Committee will assist in the solicitation, creation, ..."
From this and other comments in "The Book", perhaps the co-authors are proposing that the MAA take on this role for this project. I notice that that commitment was from 1997, but that the co-authors are confident that the MAA today would re-affirm that commitment. Has anyone contacted the MAA recently just to double check this? I'm also curious why, given the 79+ years (as of 2021) that Society of Science has affirmed its support for STS, the MAA is only committing to a 2-3 year commitment for this journal? I think at the very least if we are asking for 10 years of funding to get started, we need to ask the MAA for 10 years of the kind of support they are offering. If they limited their support to 2-3 years for a reason, we should understand why.
It is also possible that George is proposing, per the message I'm quoting, that the Society of Science itself act as our mathematical champion for this project similar to what they have done for STS. This is definitely an option especially considering that STS does include mathematics and has produced two Fields Medalists. As George also notes, the drawback here is that their support of mathematics is often quiet compared to their support of other branches of science. Ideally I'd like to see an organization that can advocate loudly for mathematics--and specifically mathematics as opposed to tech or any other branch of science--when the need arises.