Considering that X/Y and ORAS added a ton of new movesets to Pokémon from previous generations, I reckon that Sun & Moon will do the same thing.
For example, X & Y gave Squirtle and it's evolutions access to Dragon Pulse and Aura Sphere via breeding. Another example on the level-up spectrum? Entei can also learn Sacred Fire through Move Relearner.
ORAS also gave Delphox the ability to learn Dazzling Gleam by TM and Xatu finally got access to Air Slash naturally.
There are quite a few examples, but I'd rather not stall you on that part.
To me, this proves that Sun & Moon will most definitely continue the trend in some fashion.
Assuming that is the case, here are some Pokémon I'd like to see have new moves added to their movepools.
1. Feraligatr
Dragon Rush would be a very good addition to it, since Aggron and Rhyperior can learn it through breeding. Should Feraligatr Mega Evolve into a Water/Dragon Type, Dragon Rush would benefit from that strong type combo. Bonus points if the Mega has Sheer Force as it's Ability.
2. Yanmega
Since it is known for using supersonic attacks, Boomburst would be a solid addition to it's moveset. Vibrava could learn it in ORAS, so it would make sense for something like Yanmega to know that attack in Sun & Moon, but that is merely my opinion.
3. Togepi, Togetic and Togekiss
Moonblast is the ideal addition to their movepool, and there is still a lot of opportunity for Game Freak to incorporate extra moves for their movepool, as shown with a lot of Pokémon from Gen III onwards. Moonblast would benefit from Serene Grace, which will give Togekiss even more tools to work with offensively.
I'd also like to hear which Pokémon that you think deserve some extra moves in their movepool in Sun & Moon, or Gen 7 in general.
For example, X & Y gave Squirtle and it's evolutions access to Dragon Pulse and Aura Sphere via breeding. Another example on the level-up spectrum? Entei can also learn Sacred Fire through Move Relearner.
ORAS also gave Delphox the ability to learn Dazzling Gleam by TM and Xatu finally got access to Air Slash naturally.
There are quite a few examples, but I'd rather not stall you on that part.
To me, this proves that Sun & Moon will most definitely continue the trend in some fashion.
Assuming that is the case, here are some Pokémon I'd like to see have new moves added to their movepools.
1. Feraligatr
Dragon Rush would be a very good addition to it, since Aggron and Rhyperior can learn it through breeding. Should Feraligatr Mega Evolve into a Water/Dragon Type, Dragon Rush would benefit from that strong type combo. Bonus points if the Mega has Sheer Force as it's Ability.
2. Yanmega
Since it is known for using supersonic attacks, Boomburst would be a solid addition to it's moveset. Vibrava could learn it in ORAS, so it would make sense for something like Yanmega to know that attack in Sun & Moon, but that is merely my opinion.
3. Togepi, Togetic and Togekiss
Moonblast is the ideal addition to their movepool, and there is still a lot of opportunity for Game Freak to incorporate extra moves for their movepool, as shown with a lot of Pokémon from Gen III onwards. Moonblast would benefit from Serene Grace, which will give Togekiss even more tools to work with offensively.
I'd also like to hear which Pokémon that you think deserve some extra moves in their movepool in Sun & Moon, or Gen 7 in general.
