Deprecated categories in contributions-guide

[alanboy]

In vsts-extension-samples/contributions-guide/vss-extension.json the contributions used are no longer usable:

https://github.com/Microsoft/vsts-extension-samples/blob/81ccdf0f7dba36f642080e3f9b9d5b90af1dea17/contributions-guide/vss-extension.json#L9-L14

If you use them, you get an error from ADO saying that the configurations are outdated and you should be using the categories in here: https://docs.microsoft.com/en-us/azure/devops/extend/develop/manifest?view=vsts#required-attributes

Very strangely, I updated my extension to get a screenshot for this bug, but it got accepted. So this validation only applies to new extensions?