Index Management app needs a11y tests coverage. An example of a11y functional test can be found in this file that contains a11y tests for the ILM plugin.
A11y testing should cover every view of an app that means loading every tab in Index Management and trying to open every flyout and modal. Tests should also cover all available edit forms.
Documentation for a11y testing in Kibana can be found here.
Meta issue for accessibility testing in Kibana can be found here.