"NASA has initiated a process that raises questions about the future of its Orion spacecraft. So far, this procedural effort has flown largely under the radar, because it came in the form of a subtle Request for Information (RFI) that nominally seeks to extend NASA's contract to acquire future Orion vehicles after Exploration Mission-2, which likely will fly sometime between 2021 and 2023. Nevertheless, three sources familiar with the RFI, who agreed to speak on the condition of anonymity, told Ars there is more to the request than a simple extension for Orion's primary contractor, Lockheed Martin. Perhaps most radically, the RFI may even open the way for a competitor, such as Boeing or SpaceX, to substitute its own upgraded capsule for Orion in the mid-2020s."
Keith's note: There are a number of off ramps developing whereby NASA could shed Orion - even SLS. Stay tuned.