No lawyers familiar with how administrative agencies work agree with that assessment. And that is, importantly, not how rulemaking works at administrative agencies.
EDIT: Administrative agency "rulemaking" is constrained by a fixed set of procedures that an agency must follow in order to "promulgate" a rule. First, they must publish a draft of the proposed rules, allow for several weeks or months of public comment, spend several weeks or months reviewing those comments, revise the rules as needed based on the comments received (or explain why no revisions are necessary), and then finally publish the finalized rules in the Federal Register.
Comments made by a single employee do not convey, or constrain, an agency's position on matters within its scope (unless those comments are made in, and pursuant to, a legal proceeding, in which case they are binding only for the limited scope of that legal proceeding).
The closest this article comes to your claim is when it says the case “could settle the turf war between regulatory agencies like the Commodities Futures Trading Commission, the Consumer Financial Protection Bureau and the SEC, all vying for jurisdiction in the space” [1].
A Ripple win would apply to the facts and circumstances of Ripple and XRP, and isn’t expected by anyone informed to set a broad precedent constraining the SEC’s powers.
EDIT: Administrative agency "rulemaking" is constrained by a fixed set of procedures that an agency must follow in order to "promulgate" a rule. First, they must publish a draft of the proposed rules, allow for several weeks or months of public comment, spend several weeks or months reviewing those comments, revise the rules as needed based on the comments received (or explain why no revisions are necessary), and then finally publish the finalized rules in the Federal Register.
Comments made by a single employee do not convey, or constrain, an agency's position on matters within its scope (unless those comments are made in, and pursuant to, a legal proceeding, in which case they are binding only for the limited scope of that legal proceeding).