Daughter had a return to USA flight home from Portugal cancelled due to this widespread "technology issue". ticket was booked via expedia, it was several different airlines (including Air France)... portugal to spain to france to USA. She bought expedia's travel insurance.

Airlines told her to call expedia for help. Expedia sold her another ticket ($1500 x 2) then told her to apply for reimbursement.

/1/ Will the EU261 compensation rules apply, or is this an "extraordinary event"?
/2/ Will her return tickets be covered by Expedia's travel insurance? or by the fact that even without insurance, they are responsible to get her home?
/3/ Or in the end, will they simply be out the cost of those return tickets?