Deoxys Legacy Moves?

Deoxys Attack is pretty much useless and not worth wasting TMs on

Well, if it becomes a legacy move exactly like Mewtwo's Shadow Ball, it won't be a problem, because they will announce that it will go legacy. But I doubt that Deoxys merits this treatment, at least for the attack form. Now, Defense Deoxys might be a terror in the great league, so that could get special treatment.

The reason Shadow Ball and Hyper Beam went legacy for Mewtwo was so that trainers who caught theirs from EX raids would have something to show for it. The only move all Deoxys formes hare is Psycho Boost, which I hope they don't make legacy since it slays in PvP and is its signature attack.