About three weeks ago something very similar happened with KLM-UK in Amsterdam: Flight to Manchester delayed (tech) prior to boarding of pax. After just over an hour pax directed to board aircraft that had been due to go to Stansted. Presumably the STN pax got away without too long a delay...
I am guessing but, without making a judgement, it seems to me that the airline has the choice of one flight delayed several hours and the resulting compensation, or two flights with shorter delays and no compensation. One choice makes sense for the airline, the other will raise mixed feelings from the passengers depending on their personal situation.
ND
