Clearly there may be a massive problem for Tether. Outside of Tether - I'm not seeing the ramifications, other than exchanges are going to have to use different stable coins. I remember when LTC and FTC used to be legit trading pairs on exchange websites. Whether or not Tether is legit seems pretty uninteresting to me - my trading bots regularly go through thousands of USDT, and I've never once thought to myself "Oh, I can redeem this for 1USD." It's just a utility token, and if it dies, something will fill the void after a brief panic.
To me, this just seems very overblown.