No, a synced segment cannot be updated from an import file. It can only be updated when sync runs.
For example, if today is August 7, 2025 a search with the value "yesterday" will return results for August 6, 2025....However, on August 8, 2025 the results will be for August 7, 2025.
When a revision is restored the subject, CSS, HTML, plain text and AMP versions of the email are all reverted.