New Tethers are not supposed to be issued if the price reaches $1.1, I believe the article got that part wrong.
Tether should only be issued based on the amount of USD that Tether has in its bank account / vaults (they have released a 'audit' by a law firm but not by an official auditor). Since each Tether represents exactly $1, market forces should handle the pegging. Assuming people trust that Tether does have the USD, then any price < or > $1 represents an arbitrage opportunity.
The demand for Tether comes from the fact that many exchanges are not licensed to operate in USD. Tether is used in place of USD on those exchanges, and the counterparty risk you mention is likely balanced by arbitrage opportunity.