Originally Posted by singaporeair

As you may be aware, the UPGR policy is purely based on fare class now (excluding EK Platinum). People think that travel history and patterns, tier miles, overall loyalty etc. have an impact, but they don't. The system generates a priority list based on fare class only. This is a relatively common situation, where boarding goes ahead on an oversold flight, but maybe a seat is INOP or there is some other issue that arises last minute. Generally, they will then locate the next person on the UPGR list and manually upgrade. This was most likely what happened!