I hope you don't really believe that... the market manipulation using USDT is well documented.
Please provide this well documented evidence that you have that seemingly no one else can get their hands on.
Bitcoin will fall hard if tether isn't backed... you'll know its happening when bitcoin goes up 50% + in one day. Since BTC is more weighted and tied to USDT than USD the flood of users out of USDT to BTC will for a couple hours skyrocket the currency... then it will crash hard.
I don't think that this will have a knock on effect to the USD/BTC price but it is a good point, meaning I don't think USD/BTC will increase sharply before falling harder.. If there are people with insider knowledge that Tether will be exposed within a day or so then they'll rush to sell USDT. I think the more likely route would be to sell USDT for USD however, if they have any sense they'll realise that once Tether falls then bitcoin will too.