The way the migration tool has been developed suggests that Google does not intend to develop announcement, file cabinet or list page types in new Google Sites. This means there will not be the gadgets associated with pages so if you have a homepage that shows your most recent news articles etc, this will never work nor be possible. This may only be a temporary measure but there's no way of knowing. Our best advice is to Send Feedback to Google to let it know if you're affected by this lack of fidelity in migration. Alternatively If you use G Suite Basic/Business or for Education you can contact Google Support to see if there are any plans to get more page types.
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