Originally Posted by
intuition
Someone decided to make a minor schedule change and changed flight number at the same time?
AY99/100 is not published to GDS. I'd say they are the same, not a new rotation.
Accoring to
this AY99/100 are the new flight numbers for 69/70, but that was announced before they announced 61/62. So yeah, it seems someone made a little mistake. All these three flights are bookable on finnair.com though.