Over half of GAF has logged in for the expansion.
There's a couple issues that are compounded here. First, the maps are gigantic with a lot going on in them. Second, the map pop caps are lower than other maps so in conjunction with the first issue, you have less people over more land mass. Third, things like bounties don't really reward you as well as they should. I can get more contracts killing a pack of mobs in 10-15 sec than I get for completing a bounty. They're going to need to tweak the rewards for sure. People do bounties, but they all go to one map typically to get into a zerg. Much like HoT, you have specific instances doing specific stuff. Some do bounties, some do [REDACTED] related stuff, some people are just exploring completely unrelated to events, some are doing story stuff. The fact is there are less people allowed into these maps that are flat out gigantic in terms of overall playable space and you don't really get that collective feeling of players that HoT had outside of bounties.