We would follow the Idea of Tether and TrueUSD but instant of staying on one fiat currency we would add more fiat currencies for more people around the globe.
The concept behind tether is already broken. Bitfinex and its shills are making sure to promote it but then the infinite supply of tether which can no longer be audited it without doubt a big black spot in the crypto community. What they are trying to achieve is not what crypto was made for. What their intention of doing so could be manipulation of prices like 2017 bitcoin pump and maybe more coming in future.
Yes it is true that tether is already broken. But with more transparency which would show the 1:1 back up of the stablecoin in our bank account. With that we would have a Coin which can show that it is indeed backed by his Fiat Currency.
And yes they can declare it as "illegal" but does that mean we need to stop what we are doing? No.
Yes because they will send their law enforcement against you. If you get into legal trouble with a government you will have to face consequences and so will the people using it.
Firstly we wouldn't just create different Stablecoins for all fiat currencies at once. We would grow slowly with USD, Next EUR, Next RUB, then we would look which currencies we could and should add/create. So we would firstly check our needs, what we shouldn't do and what we should do in a correct way.
People can still exchange their currencies and withdraw them 1:1.
They would no longer use it because of their personal loss and nobody would want be involved once it has been declared illegal.
The money is not vanished. We can safe the cash in a safe and if it gets illegal we can still take the cash out. Maybe a part would be in a bank account which we could not take out but we would try to get it out. But then we could offer those people to send their cash in a different way.