What are the practical impacts of the sys.dm_exec_query_stats warning in the documentation?
I've updated the documentation to be more straight-forward on the wording. The intent was to tell the user that running a query against the DMV will produce output only for items that had completed and not for items in-flight. Thus, run the workload in its entirety to make sure all is captured.

The new wording will be the following and applied the various DMVs the previous wording was incorporated into. 


  The results of sys.dm_exec_query_stats  may vary with each execution
  as the data only reflects finished queries, and not ones still
  in-flight.