Thanks ET,hope it does not happen to us.
Back to the OP-Substitution
The BHX boys advise that the substitutions were due to high loads/overbooking on an outbound and also an inbound linked to school holiday dates ( and probably no/few F pax) The EK BHX load figures for all 3 daily flights "could be exceptional" so August was a great month to launch the 3rd daily flight
SSF