...so a pity not to use it. But honestly, I'm guessing the major "sin" from the perspective of those objecting to agreements called "Article 98 agreements" as counter to the project of the ICC is the agreements themselves, not subsequent references to them. And I think as a practical matter, the certification isn't really misleading, albeit potentially confusing - US servicemembers are essentially without risk from an assertion of the ICC's jurisdiction -
complementarity, prosecutorial discretion, and judicial discretion (or politics, if you prefer) should more than adequately patch up...