There will be lots more exp methods in the patch series, you just don't get side content in a X.0 release. That's something it would be nice to change in the future. Mix up the order the content gets released because we're very fixed in a pattern.

Example: we get a deep dungeon right off the bat in patch 6.0 (unlocked during msq) and some other stuff instead of five leveling dungeons in the lv81-89 range. A 'relic' type weapon right off the bat with an expansion release would be nice too. The first step doesn't need to be very elaborate, just make something available to grind instead of coming several months after xpac launch.