Problem: ArcView 3.x theme definition queries are not preserved when imported as layers
Definition queries on ArcView 3.x themes don't get imported when importing ArcView 3.x documents into ArcMap.
The syntax for these queries doesn't match the DBMS specific SQL syntax that ArcGIS uses for definition queries for layers.
Solution or Workaround
Recreate the definition query using ArcMap rather than copying and pasting what ArcView 3.x used.