I have never seen options which only vest on a specific occurrence. Options are generally given to encourage management's success in causing the company's business to succeed.
I have seen them essentially re-priced to allow for the fact that circumstances beyond management's control caused a serious devaluing of the share value.
I interpret what has happened here as being such a circumstance (in the opinion of the Board of directors)
Shareholders may have a different opinion; but in fact the vagaries of a country's politics is usually deemed to be "beyond reason" (to quote from a famous Canadian politician's wife!!)