As shown in below screenshot, currently I see only below highlighted REST API's that are related to update management. Here is the document reference for the same.
If these REST API's doesn't help to accomplish your requirement then if interested you may share it as feature request in this uservoice or feedback forum. In general, Azure feature team would check feasibility of a feature request, prioritize against existing feature backlog, add in roadmap as appropriate and would announce and/or update the related Azure document once a feature request is addressed.
On the other hand, with the help of this and this references, you may find the same information in update management related kusto tables which you can query with the help of this REST API.