The folks whose main concern was the expansion's $US50 price tag are just going to have to suck it up — that's not changing. What is changing is what comes with a pre-purchase of the expansion for veteran players, and how players who purchased the core game over the past few months can get a refund now that the original game is included with the Heart of Thorns expansion pack.
First off, all veteran players who owned and registered Guild Wars 2 before January 23, 2015 will be getting an additional character slot for their account. This will allow players who've filled their slots already a chance to try out the new Revenant profession without deleting another character. This move addresses worries that new players were getting more of a value than existing ones, as a portion of the $US50 expansion was something they have already purchased. That means veteran players who purchase the more expensive collector's editions of the expansion will get two slots.
The second biggest player concern regarding the expansion preorder was players who had recently purchased the full game, only to have it revealed that it's included in the expansion pack, rather than requiring a separate purchase as originally outlined in the expansion's FAQ page.
This gets a bit tricky.
Players who purchased the original Guild Wars 2 between 1/23/2015 and 6/16/2015 (when the expansion pricing was announced) and pre-purchase Heart of Thorns before 7/31/2015 will receive an automatic refund for the original game — as long as they purchased it through ArenaNet directly.
Those who purchased the original game through a third-party within the same time frame cannot be refunded, but they will receive an additional character slot (around a $US10 value).
Finally, those who purchased the game within the January through June window who do not wish to preorder the expansion may request a refund for the main game, but their account info will be lost should they return in the future.
Here's a handy table created by Redditor Escath.
I'm a little dizzy, but I'm feeling much better now that we've clarified the fine details of an expansion pack we still have no release date for. Thanks ArenaNet!