In DRDL documentation, it still says:

mongodrdl produces these files using one or more MongoDB collections as a guideline, and mongobischema imports them into the Business Intelligence Connector.

This is no longer accurate. Instead, it should say something about how mongosqld uses these files. Also, note that HELP-3229 indicates some confusion over whether mongosqld needs to be restarted after a change to a DRDL file, so perhaps a note about that could be added as well, though probably to a different section.