Lists of figures and tables are not a requirement to pass the WCAG 2.4.5 criterion but are recommended.
The criterion is as follows:
Criterion: 2.4.5 Multiple Ways
Simplified Language: Ensure that there is more than one way to locate a particular page on a site, like having menu navigation, links between pages, a search function, etc.
From WCAG: More than one way is available to locate a Web page within a set of Web pages except where the Web Page is the result of, or a step in, a process.
If page breaks and a page list are included in the EPUB, the reader can navigate to the figures via individual chapters or using the page numbers, which would fulfill the multiple ways criterion. If a separate list of figures is being included in the EPUB, it is typically added to the EPUB TOC in the nav document.
The spine includes an ordered list of all the contents in the book, and it should also include an itemref for the List of Figures or List of Tables xhtml doc if one is present in the EPUB.