They would’ve already closed such positions as soon as there was margin risk. IB doesn’t have any problems instantly buying back shares for someone who shorted them. They even increased margin requirements to make sure that IB itself is protected.
They also restricted trading in those stocks to protect themselves and therefore the customers, so there is zero risk for IB.
That’s also the reason they’re bringing attention to the issue, explaining that volatile instruments are risky, while IB is always proactive and obsessed with managing risk.
And btw, they do have a right to halt trading in securities since IB customers agree to this when opening an account.
This also affects me negatively, but there are too many benefits of staying with IB, including their risk management.
Though I may open an additional account with a different broker in the future, just to have more choices at times like this.