Now that inert is implemented in browsers, essentially doing what aria-hidden could never really do - fully preventing all users from being able to access content the attribute is applied to, should this be noted for the aria-hidden attribute? That, depending on context, there may be a more robust host language tool available?

Additionally, as we are aware that use of the attribute can often be.... problematic (re: incorrect), and there have already been actions taken to re-expose hidden content when it receives keyboard focus, the question was raised to me whether aria-hidden=true should instead not prune the content from the accessibility tree, but instead mark it as "hidden". The intent there being to still expose the content via the a11y tree, but allow AT to inform users they have reached hidden content, and give them the choice to go venturing into it, or to navigate to the content that isnt' marked as hidden.