Is Ash technically the Pokemon Champion of Alola like Steven? In Pokémon Sun Moon anime, now that Pokémon League Champion is Ash and there are no Elite Four, does this make Ash the Pokemon Champion of Alola?
Yes, Ash is now considered a Pokemon champion of Alola like Steven.
However, Ash already was a 'champion' before becoming the champion of Alola, the champion of Orange Islands.

However his victory on Orange Islands is often disregarded due to the unconventional 5 gym battles without Elite Four, a Champion, or a Conference.

As mentioned on the Pokemon fan Wiki the following is required to become a champion


  A Pokémon Champion is a trainer who has beaten a region's Gym Leaders (in Alola's case, all 7 trials and totem Pokemon), Elite Four, and the previous Champion.