If my outbound flight is cancelled and I don’t like the alternative offered so I buy a new one-way ticket on another carrier, will the original airline cancel my return flight?
In most cases, yes. If the original airline with the cancelled flight (Airline A) agrees to accommodate you on another airline (Airline B) because they are unable to do so on their own airline, then your return would be protected. However, if none of the alternate arrangements offered by Airline …