If the playtest is any indication, the paladin class entry will mention which alignments the paladins of various oaths tend to. I'm pretty sure that the Oath of Devotion one we are seeing is going to mention something along the lines of LG. Take a look at the "Oath of Devotion" intro paragraph in the October playtest for an example. It specifically mentions law and good.
So at least they are saying that the Oath of Devotion is, by default, and oath to a LG deity or principle, regardless of the paladin's own alignment.
Then there is the Oath of Vengeance for avengers, and I'm sure there is some sort of blackguard oath, and if we're really lucky (and I'm not counting on it) maybe the green knight paladin from earlier in the playtest will be resurrected for the PHB.
So what I'm saying is that they aren't removing the idea of alignment from the fluff text around the class. Only one subclass (the Oath of Devotion) is representative of what has traditionally been a paladin in D&D, and it specifically mentions law and good in the fluff.
Really, if you want to allow a paladin devoted to chaos and good, you have to refluff it, or create a whole new Oath, because the book probably isn't going to offer that option.
So when a new player is opening up the book and reading the classical knight in shining armor subclass, they are going to read that they swear an oath of devotion to law and good, and that is going to be their first exposure to a D&D paladin.