It probably has to do with lots of pilots leaving the company more than anything else but yes there is some expansion factored into that formula.
Over 50 pilots have left so far this financial year with many more hoping for that call to real airlines.
Join Emirates with risk to your health.
If you really want to come to the muddle east think about EY or QR. they both pay more than EK and have significant shorter upgrade time. Probably 3 times less wait.