When we call explain for a command on a sharded cluster, we call into this function which unconditionally passes in false when calling into useTwoPhaseProtocol.

When we call into useTwoPhaseProtocol, we end up returning false for legacy time-series collections but only because we perform this check on the view namespace, and this will return true because views do not have routing table info. This does not appear to me to be intentional, but rather a side effect.

For viewless time-series collection, we will progress and end up adding this dummy target doc to the explain output. The fix here would be to properly detect whether we are attempting to explain a command on a timeseries collection.