It seems like an oversight that metrics have been added to one or the other of "Slow query" logs or the profiler data documents. They are both system diagnostic tools, and it seems like an unpleasant user experience (a surprise) that metrics would be available in one but not the other.

OpDebug::report puts information into "Slow query" logs. Whereas it looks like OpDebug::append is leveraged by the profiler. Lastly there is a OpDebug::appendStaged function for creating a CurOp report filter (returns a lambda function) of the operations returned (added by SERVER-49102) used in ProfileFilter.

A new metric must be added in three places to ensure it is included in both profiler (and filtered profiler) and "Slow query" results. These paths should be documented – there is none to inform developers where to add code – and merged as much as possible