Are you confirming that this fix is in the Winter release? Can we also get the docs fixed? They need to give an example of the syntax, otherwise we're just guessing.
I didn't see it mentioned here Release Notes: Winter '17 - Marketo Docs - Product Docs, but then again, I don't think "fixes" like this are included in the release notes.
It is not in the upcoming release, but it's been completed and will be released in ~1 month (early April).
It's in our syntax doc:
Default value (optional)
mktoDefaultSnippetId: The numerical ID of the Marketo Snippet that should appear by default (will only work if a Snippet with that ID exists and is approved in that workspace).
Does this apply to shared snippets? All of our snippets are contained in the default workspace and shared across 23 country workspaces.