Whether or not the column alias is ignored seems to depend on a number of things...
1. The version of the MySQL JDBC driver. A old bug logged against Netbeans noted the problem for 5.1.5 but not 5.0.7. For reference:
2. Whether the column is just a column, or used in an expression. Using MySQL 5.7 with the 5.1.27 driver against SQL Developer 4.1.3
This works: select trim(district) as Zone from city;
or: select district||'' as Zone from city;
but not: select district as Zone from city;
3. The responder in the other discussion looks to have been using an Oracle gateway, not the MySQL driver, so I doubt that's meaningful to us.
So one could suspect SQL Developer needs the same fix as the Netbeans folks made, specifying getColumnLabel instead of getColumnName, but I haven't time to research that. Moreover, if this ability is not needed to support migration from MySQL to Oracle, any bug would likely be low priority.