During their troubleshooting, engineers evaluated the option to “use as is” with the high-degree of available redundancy or remove and replace the box. They determined that due to the limited accessibility to this particular box, the degree of intrusiveness to the overall spacecraft systems, and other factors, the risk of collateral damage outweighed the risk associated with the loss of one leg of redundancy in a highly redundant system. Therefore, NASA has made the decision to proceed with vehicle processing.
I like the wording used, “degree of intrusiveness to the overall spacecraft systems,” which roughly translates into taking the entire spacecraft apart, reassembling it, and testing everything again.
All in all this seems like the right call. At a certain point, the risk of bigger delays coming from the process of fixing this issue is more than the risk on this particular flight. We have yet to see political support of Orion and SLS be eroded in any meaningful way, but every increasing delay has to catch up at some point.