I've been seeing this warning message when calling New-OSCustomizationNicMapping for a while now. No one seems to have commented on it anywhere online, which is odd.
I create my customization using New-OSCustomizationSpec and pass it to New-OSCustomizationNicMapping.
What is the proper thing to do here? Continue to ignore this nonsensical warning?
The warning is not really nonsensical.
It just says that you can only specify 1 value on the OSCustomizationSpec parameter of the New-OSCustomizationSPecNicMapping cmdlet.
What you are doing is completely valid, you just get the warning in any case.
If you don't want to see these kind of depreciation warnings, you can use the Set-PowerCLIConfiguration cmdlet with the DisplayDeprecationWarnings parameter set to $false.
Which a lot of users are doing is my impression.
There are two things being claimed here:
1) the parameter is obsolete
2) the parameter no longer accepts multiple values
Which is correct?
The wording might be confusing, but there is only 1 claim, namely the 'multiple values' option.
Not to split hairs, but the wording is wrong if the parameter is not in fact obsolete. The parameter is not going anywhere - it's just that its allowed range of values is changed.
I suggest you launch your correct conclusion at PowerCLI Ideas and ask for a better review of these warnings.
To be honest, this is not the first time a deprecation warning was open for interpretation.