Amazon can give more shifts to non striking workers, train new employees in a matter of hours, leverage labour hire companies, bus in workers from other facilities, lean on FBM and other 3PL providers, increase automation. They also have a massive network of fulfilment centers and can easily just ship in fulfilled orders from elsewhere using non union trucking and last mile.
Amazon also has deep pockets and a long time horizon, so worst case they'll just allow the facility to be shut down by strikes and let their customers know it'll take another day to deliver their order from elsewhere.