Eagle: show package type in schematic
Options:

You can symply write the package information directly in the schematic.

You can add text to the symbol that just expands a special attribute, like PACKAGE.  The text string would be ">PACKAGE".  Nothing would shown in the schematic unless the PACKAGE attribute existed for that device.

In the device, you then set PACKAGE to whatever you want to show in the schematic for each variant.