The changes from SERVER-83964 to enable a fix for aggregate commands (changes to query_stats_agg_cmd_collect_on_mongos.js and cluster_aggregate.cpp) in commit  allowed query query stats to collect stats even if the database doesn't exist. 

The commit depends on some changes made from SERVER-69836.

This ticket is to investigate if it should be a goal to collect stats on 7.0 for aggregate commands with no database - did the changes from SERVER-83296 cause the issue in SERVER-83964 or did it already exist? Looks like before the commit, running commands with no database did not error out, so we should collect query stats for it. 

If the issue already existed, investigate how to collect query stats on collections with no database on 7.0. Might involve a backport of SERVER-69836. That ticket has downstream changes that will need to be added if it is backported.