I don't see them introducing true dual typed moves due to calculations and alternation effects that would be applied to them. I can see maybe a few moves like Flying Press surfacing if we are lucky since it only calculates half the damage formula once (STAB, item effect and terrain/weather effects)
Giving the move an effect that also deals " --- " Type damage is easier on the programming as all it takes into consideration is the defensive matching of the second type and matches it with the defensive matches of the originating type.
Like in Flying Press' case.
While it is a Fighting Move, only the Fighting Type will get STAB and items that boost fighting type damage will boost Flying Press, once those calculations are applied, it matches Fighting's and Flying's match ups to the type of the defending Pokemon. The move itself can be preprogrammed to work specific ways against types, mush like how Dry Freeze works since it automatically does Super Effective damage to Water types, but cannot double that damage if changed to Electric type.
Likewise, if changed to Electric, Flying Press now does Electric/Flying Damage and gains STAB bonus if the Pokemon is Electric, will get item bonus if holding an item that boosts electric attack damage, and will get a bonus if used in Electric Terrain. Flying Type and Items don't affect the move at all since it isn't a Flying type attack.
So, I don't see a true dual typed move appearing, but another Flying Press like move isn't out of the question.