If by “against” you mean “inconsistent with” as defined above, then I agree, but then the statement becomes trivial. But maybe I have a simpler way around this…
…well, can’t every (normative* non-libertarian) statement be “Yeah, so?”-ed by the libertarian (every performer of Action L)? Because every normative statement can (and generally is) “Yeah so?”-ed by anyone who doesn’t share the norms the statement refers to. See Lilburne’s brief post on casuistry here Valid Casuistry: Deriving Ought from Ought
Before I answer this, the whole concern may be circumvented by the above, which I may be quite late in noting because I think the “Yeah so” issue was brought up before, but I didn’t see this way of resolving it at that time.
*Naturally, non-normative statements like, “Don’t homestead that stick, it’s a snake!” or other consequentialist statements or statements of fact wouldn’t be “Yeah so”-ed