Yes, of course those things will be revisited (questionable if any greater importance will be added), but for something that is the basis of and the general theme of the series the reveal of the mystic weapons and city couldn't have been more anticlimactic if they tried.
edit: Fell about as flat as Krang showing up in the last film. Some supposedly "big" aspect of it and then...
Okay, so that happened, next scene.
Why did those big guys after the cat-squirl-monkey-dog-pokemon thing have little dogs with them?
And as I write that I'm theorizing that the dogs were actually in control of the people and the cat-dog thingy they were after was an escapee from some mystic dog experiment.
As I'm not too familiar with Pokemon, I do however sort of want to give this creature a "experiment" number from the Lilo and Stitch series...