Currently, there are 3 places that says "Namespace x.y is a timeseries collection".

https://github.com/10gen/mongo/blob/883238375b56d7a4a11f48583a5f79a5f7192d87/src/mongo/db/catalog_raii.cpp#L303
https://github.com/10gen/mongo/blob/883238375b56d7a4a11f48583a5f79a5f7192d87/src/mongo/db/catalog_raii.cpp#L434
https://github.com/10gen/mongo/blob/883238375b56d7a4a11f48583a5f79a5f7192d87/src/mongo/db/commands/run_aggregate.cpp#L765

Suggestion:

• Reword error in catalog_raii as "Taking x.y lock for timeseries not allowed"
• Reword error in run_aggregate as "Cannot run aggregation on timeseries ns x.y"