The new player aspect is troubling, and I've been saying it for months.
It's pretty unique from an MMO standpoint to gate off an expansion behind such a huge requirement. Normally you just have to be the right level and off you go.
I think SE kind of painted themselves into a corner by not having the ARR story be self-contained. The way the story works, you HAVE to complete it before going to Ishgard makes any sense. This is terrible for a number of reasons, but the biggest one is that it makes the expansion not draw in brand new players (or it does and they feel cheated when they hear what they have to do to play with the new shiny). I expect SE to take a hit in the reviews of Heavensward for this one. It may otherwise be a brilliant expansion, but this one thing alone is going to turn off so many people who would otherwise have picked the game up.