A yoga instructor tweeted this advice:

( https://twitter.com/sentfromdevyn/status/1026536048384507904 )
She just meant this as a temporary release of tension, but many people replied with "well actually" explanations that the tongue belongs on the roof of the mouth. In fairness, the original tweet assumes that is the default tongue position. I am surprised by the prevalence of knowledge about correct oral posture, the n-spot, preventing bruxism, the impact on facial form, etc., and I am also surprised by how many responses indicated that they have always instinctively kept their tongue on the roof of their mouth. I didn't notice anyone owning up to a low resting tongue position. A few years ago this concept would have been a revelation for me. Maybe there's just a selection bias that such people aren't participating in the conversation.
i hope one day someone will make this problem famous
I would say that correct tongue posture is more prevalent than we assume. After all, I know lots of us know people who never needed braces and/ or people with great posture and maxillary development.
This posture becomes instinctual if reared properly (breast feeding mainly). I am not surprised many people instinctively do this because it's the same as standing straight. It is default. I mean CroMagnon man certainly had the development present to indicate tongue posture was proper even back then.
What is revolutionary is the fact people are finding out how functional it is. The way your breathing improves, the way you uptake and balance NO with CO2, the way you filter out air better, the more your airway expands, the better your neck posture becomes, etc.