I think it would be wonderful in its effects (I am not a native English speaker), but I don't like the "mandate" part.
As for the other point you are making - the language and culture were developed to work around physical issue of not hearing. Those who have learned the language can continue to use it after regaining hearing. I don't see why those who can hear couldn't learn it if they wanted to (e.g. to communicate with someone who decides to not pursue treatment for whatever reason). I also don't see why preserving something, that solves a problem that now has a better solution, is so important.
Since you are very eager to police what I can or cannot do, let me return the favor: you can stop projecting beliefs you are angry about on other people and you can stop fighting those people over those projected beliefs.