Get-Module -ListAvailable doesn't respect DefaultPrefix

Prerequisites

• Write a descriptive title.
• Make sure you are able to repro it on the latest released version
• Search the existing issues.
• Refer to the FAQ.
• Refer to Differences between Windows PowerShell 5.1 and PowerShell.

Steps to reproduce

Use any module that has the DefaultCommandPrefix defined in the module manifest. I modified one of my modules to test with.

In Windows PowerShell, if I have a module that uses a defined prefix, this works as expected.

Expected behavior

PS C:\> $mod = Get-Module PSChristmas -ListAvailable
PS C:\> $mod.ExportedFunctions.keys
New-xElfName
Get-xPSChristmasPresent
New-xPSChristmasGreeting
New-xPSChristmas
Show-xPSChristmasMessage
Invoke-xJingle
Write-xFestive

The module is NOT loaded into my session. But not in PowerShell 7. PowerShell 7 fails to use the prefix.

Actual behavior

PS C:\> $mod = Get-Module PSChristmas -ListAvailable
PS C:\> $mod.ExportedFunctions.keys
New-ElfName
Get-PSChristmasPresent
New-PSChristmasGreeting
New-PSChristmas
Show-PSChristmasMessage
Invoke-Jingle
Write-Festive

If I import the module in PowerShell 7 and re-run the command then it works.

PS C:\> import-module pschristmas
PS C:\> $mod = Get-Module PSChristmas
PS C:\> $mod.ExportedFunctions.keys
Get-xPSChristmasPresent
Invoke-xJingle
New-xElfName
New-xPSChristmas
New-xPSChristmasGreeting
Show-xPSChristmasMessage
Write-xFestive 

Environment data

Name                           Value
----                           -----
PSVersion                      7.1.3
PSEdition                      Core
GitCommitId                    7.1.3
OS                             Microsoft Windows 10.0.19043
Platform                       Win32NT
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

Also tested in 7.2.0-preview.4 with the same results.

Reproduce the issue with a module manifest that defines DefaultCommandPrefix, then compare Get-Module -ListAvailable with the behavior after Import-Module. Trace how exported functions are populated for the list-available path. Done means the listed exported function names include the manifest prefix before the module is imported.