I can imagine that ANZAC sometimes can predict that Egypt is (temporarily) going to be abandoned next turn and their dudes there have to do something now (else they will be the sole defenders against Italy next turn). So then it is either attack south or retreat north. If their attack succeeds, the UK can land their aircraft next turn in Anglo, strengthening their position there.
If there is no immediate ‘retreat order’ on the UK for next turn, ANZAC emptying Anglo can also pave the way, i.e. ‘can open’ this area for the UK ARM + MECH into Ethiopia and Kenia.
Or, simply they provide a better landing spot for UK aircraft next turn.
Right now I can’t think of anything else.