This is not something that can be changed as all existing apps using the Helix streams endpoint
Thank you for answer. Yes, I understand than changes in current response data is very sensitive to apps and it really not allowed.
But Twitch can add new method to API for getting offline info and add new topic to webhook hub topic, for example Stream Info Changed or something similar. And it will not affect existing applications.
Or Twitch removed Stream offline info by some reason? Generally why in the new api there is no this method?