re: Did Arya time travel or receive whispers from Bran?

Yes, they have cut a lot of fat, combined characters, and truncated storylines.

But the overall gist is going to be the same as what GRRM has planned.

Any major changes in the eventual book (that I suspect is pretty much done but is being held back to let the show finish) are going to be made in reaction to fan vitriol on the internet.

It's like when people freaked out about Stannis burning Shireen as if it was something he'd never do and then GRRM confirmed he does in fact do that under slightly different circumstances. LINK

Yes, some things are different than the books but they are not going wildly off track. They are following the outline he gave them.