The official Pokémon movie website has updated. Translations of the new entries follow:

The Title of the 2016 Pokémon Movie has Been Announced! It's Called "Volcanion and the Ingenious Magearna"!

The title of "Pokémon the Movie XY&Z", the Pokémon movie that premieres all across Japan Saturday July 16th, has been announced!
It's called "Volcanion and the Ingenious Magearna"!

Satoshi and the mythical Pokémon Volcanion are connected by the bonds of fate.
The curtain rises on the hottest battle in Pokémon history, centered around an artificial Pokémon hiding an unknown power!

Check out the newly updated story as well:

Story

As Satoshi and his friends journeyed onward,
a huge Pokémon suddenly fell from the sky in front of them!
Appearing from the cloud of dust whirled up from the impact of the fall
was the mythical Pokémon Volcanion!
It turns out that Volcanion, who lives in the secluded "Nebel Plateau"
together with Pokémon that have been injured by humans
actually has an intense hate for all humans.

Volcanion completely ignores Satoshi and his friends,
and attempts to hurry away,
but for some reason Satoshi ends up getting pulled along with it.
Volcanion makes a run for it, and Satoshi gets pulled along.
Incredibly, without either of them noticing,
the two ended up linked together by a strange chain!
Even though they want to get loose from this chain, it proves impossible.
With no other choice,
Volcanion started running off towards "Azoth Kingdom" while pulling Satoshi along with it,
constantly fighting with him on the way.



Meanwhile, Cabinet Minister Jarvis from Azoth Kingdom,
a city of super-machinery where gigantic cogwheels are constantly rotating,
has obtained the ultimate invention he has been searching for for so many years.
It was the artificial Pokémon Magearna,
which was born in the kingdom 500 years ago but since went missing,
as well as the unknown power called the "Soul Heart"
said to reside inside Magearna.

As Jarvis plots to use this power
to rule the kingdom,
Volcanion was attempting to retrieve Magearna,
who got abducted from the Nebel Plateau!
"Ain't no way I'll ever forgive the humans!"

Will Volcanion and Satoshi manage to work together
and save Magearna while linked together?
And what is the true power the "Soul Heart" hides?
It's time for the hottest battle in Pokémon history to begin!



What is the power hidden in Volcanion's arms!?

Volcanion violently expels boiling steam!
Its arms can move freely and are split in two; the steam launched from them packs a punch! With this steam it is said to be able to blow away mountains and use the thick fog to hide itself. Because it possesses both the Fire and Water type, unlike other Pokémon before it, the water inlets of its arms can launch both Fire type moves and Water type moves. Also, the blue color of the windows on its arms seems to be related to the remaining water in its body.
For Volcanion, who uses fire and water to create steam explosions within its body and launch moves, water seems to be the source of its energy.

Magearna

Magearna
Another mythical Pokémon debuts, hot on the heels of Volcanion!
The lovely Magearna, with its metallic body, is an artificial Pokémon born by human hand 500 years ago!!

Species: Artificial Pokémon
Height: 1.0m
Weight: 80.5kg

Sources: http://www.pokemon-movie.jp/news/?p=1982, http://www.pokemon-movie.jp/ and http://www.pokemon-movie.jp/story/