As you might remember, referendum 193 aiming to make RMRK token sufficient was discussed, submitted and approved by the community. However, the call did not execute succesfully and RMRK token failed to be defined as sufficient on Statemine: the message didn't have root origin, it had Xcm origin.
The RMRK sufficiency proposal was passed via referendum, giving it the most powerful Root origin at dispatch. But within the proposal was a message to Statemine with an Xcm origin, normally used to express things like "majority of Council" as an XCM Multilocation.
The privileged Assets origin on Statemine expects:
EnsureOneOf<EnsureRoot<AccountId>, EnsureXcm<IsMajorityOfBody<KsmLocation, ExecutiveBody>>>
As in, the origin should either be "Root" or "The majority of the executive body (Council) on Kusama)". The USDT proposal used Superuser (a.k.a. Root), so it passed the EnsureRoot check. The RMRK one, however, had downgraded Root to Xcm, so when the message arrived, it went down the EnsureXcm route, to which the filter said, "that's not the majority of the Council," causing it to reject the origin.
This proposal, a sole council motion, ensures the majority of Council to enact the proposal in the right way, since the same proposal was already approved by the community.
Please review and vote at your convenience!