Because of a strike?
I do.
What's the use of rebooking a trip if you can't make your trip anymore, due to the act of a 3rd party? (=strikers)
Remember, Eurostar (trains) are commercial institutions, not like NGBE/SNCB/NMBS or DB (partly) public holdings.
Should SNCF (Fr) stop all trains on Friday, and there's no way to rebook to a simular date, either they propose a (decent) flight, or refund. Eurostar is not responsable for the strike here, but suffers as well.
But 9 of 10 times Eurostar is left alone, so they can do their few kms on French railway.