Not an intensive flyer of EK, so I thought I'd pose a question regarding flight number changes. I've purchased a ticket which includes flight EK 654 on February 9. My TA informed me yesterday that the flight number has been changed to EK 8654. No changes in equipment, flight times, etc.

Looking at Expertflyer, it shows that EK 654 has been cancelled and actually doesn't show the new flight being added. What potentially could be the reason for a seemingly meaningless flight number change?