This has been fixed for the 'description', but upstream has added new question which suffers from the same:

    [0 root@qeos-231 ~]# preupg-content-creator 
    Specify the upgrade path (like RHEL6_7) where the module will be stored: RHEL6_7
    Specify the group name which the module belongs to [system]: 
    Specify the module name which will be created [packages]: 
    Would you like to create a BASH or Python check script? [sh/py] Bash is default. 
    Select either 'sh or 'py'.
    Would you like to create a BASH or Python check script? [sh/py] Bash is default. sh
    sh
    Specify the script name which will be used for the assessment: [check.sh] 
    ....

Another thing, I have noticed that the Doc text is inacurrate.

This bug is not just about the one question but about the behavior in general; when there is a denoted default value, pressing Enter should mean accepting that value (otherwise there's no point in having a "default" value).

Can you please update the text?

Tested with preupgrade-assistant-2.1.10-6.el6.  All options with default values are now correctly applied on Enter:

    [0 root@qeos-29 ~]# preupg-content-creator
    Specify the upgrade path (like RHEL6_7) where the module will be stored: RHEL6_7
    The path RHEL6_7 already exists.
    Do you want to create a module there? [Y/n]? ^C
     Content creation was interrupted by user.

    [0 root@qeos-29 ~]# rm -rf RHEL6_7
    [0 root@qeos-29 ~]# preupg-content-creator
    Specify the upgrade path (like RHEL6_7) where the module will be stored: RHEL6_7
    Specify the group name which the module belongs to [system]: 
    Specify the module name which will be created [packages]: 
    Would you like to create a BASH or Python check script? [sh/py] Bash is default. 
    Specify the script name which will be used for the assessment: [check.sh] 
    Specify the solution file which will be shown in the report: [solution.txt] 
    Specify the module title: haha
    Would you like to specify the module description? [Y/n]? 
    Write the module description: zz
    preupg-content-creator generated these files to be updated:
    - the module was created in the /root/RHEL6_7/system/packages directory.
    - the INI file which defines the module is RHEL6_7/system/packages/packages.ini.
    - the check script which provides an assessment is RHEL6_7/system/packages/check.sh. Update it before you use it.
    - the solution text which informs about incompatilibies is RHEL6_7/system/packages/solution.txt. Update it before you use it.

    For testing content run these two commands:
    - preupg-create-group-xml RHEL6_7/system/packages to create XML file
    - preupg -c RHEL6_7-results/system/packages/all-xccdf.xml
    [0 root@qeos-29 ~]# ll


The actual module content meets expectations as well:

    [0 root@qeos-29 ~]# head RHEL6_7/system/packages/*
    ==> RHEL6_7/system/packages/check.sh <==
    #!/bin/bash

    . /usr/share/preupgrade/common.sh

    #END GENERATED SECTION

    ### For more information see 'man preupg-content-creator' or 'man preupgrade-assistant-api'.


    ==> RHEL6_7/system/packages/packages.ini <==
    [preupgrade]
    check_script = check.sh
    content_description = zz
    solution = solution.txt
    content_title = haha


    ==> RHEL6_7/system/packages/solution.txt <==
    [0 root@qeos-29 ~]#

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHBA-2016-2616.html