Any updates to the manual are added online. You can find these updates here on the manual's website. This will include new nomenclature approvals.
Ex:"We recommend dual reporting, such as mpox (monkeypox), at first mention to ease adoption of the new terminology."

The NLM Catalog allows you to search journals referenced in the NCBI Databases (ie. PubMed, etc.) to find the AMA approved journal title abbreviations.