When enabling the rank fusion feature in a non-FCV-gated context, $setWindowFields queries meeting the following criteria can fail during the upgrade process:

1. $setWindowFields using $rank, $denseRank, or $documentNumber
2. running on an unsharded collection in a sharded cluster
3. running on a timeseries collection OR in a pipeline that includes complex stages before $setWindowFields, preventing sort pushdown

To avoid these failures, we will limit the use of the new outputSortKeyMetadata $sort field and $rank implementation depending on that output to $rankFusion contexts.