I’m not Twitch Staff I can’t answer that.
In my opinion, people use this API to then connect to the stream video and that then bypass adverts and other infrastructure that the embed players provide. (Things like chat and Twitch extensions).
So I don’t think Twitch will consider providing this as an official API. Since they don’t want you to create “non standard/off platform” players.
Many developers doing something they are not supposed to be doing need this function.
Is what you meant to write. It’s not documented, as Twitch doesn’t want you to use it. Hence you are not having this issue calling an API you are not supposed to be calling.