Very related to this question: Accessible Disabled State but that is about how to style disabled buttons to make them accessibility compliant, but my question is slightly different.
Is it actually an accessibility requirement for disabled features to be contrast compliant?
You are not hiding functionality from visually impaired people by making it grey on grey because the feature is unavailable to everyone, so they are not missing out on features because of this. Yes, it's always better for everything to be contrast compliant, but that might not be relevant here.
The situation is this - we have to disable features of our web application when the system is undergoing scheduled maintenance. Therefore we don't want to remove the buttons altogether because we want the user to know that the feature is only temporarily unavailable. Additional messaging is provided on the page stating that some features are unavailable.
We designed a standard inactive state button (dark grey text on lighter grey button background) but it has come back to us with the concern that it may be failing DDA compliance. However I disagree with that concern for the reasons I state above. Am I mistaken, or is it OK to have grey-on-grey buttons for such situations?
Note: I'm not looking for any alternative solutions (leave that to the linked questions) my query is specifically about whether or not this is an accessibility concern.