>There are people that think Greninja can't create bubbles on the surface of it's tongue just because we can't see them in the leaked shots.

Seeing as Froakie can control it's bubbles mass, the next logical step in an evolution would be complete control over the bubbles, Greninja can obviously materialize them, if Froakie can control them, then there is no reason to suggest why Greninja somehow can't, much like how Cyndaquil line materialize fire on their backs Greninja would most likely be able to create it's bubbles at will.