I won't mind a SWTOR thing, where if you reach the new contents level you can skip the old content and the choices are defaulted depending on your class.
FFXIV doesn't have choices so the story won't change.
Personally I would skip ARR and the patches since they had so much padding, especially the 2.x patches. They were really one of the worse MMO experiences I had.
HW's story is amazing so I can easily see myself running it again on alts.
HW's classes are another thing, sure they start at 30 but you'll need to go through hell of the patches in order to even get to them.

You can tell that I'm not a fan of half of ARR and the patches , I won't mind if they cut half of the filler quest out...