i think we are getting things as soon as they're done, which is why we currently don't get huge previews on updates.
in other games, content is being stored untill a point where they can release them alongside with many other things.
in FFXIV's case, things are currently being developed, tested, and as soon after that we get them right away.
it's not like SE currently holds back with releasing content/fixes, more like they are working very hard, which is why we sometimes only get half of the cake (like the battle system related changes, and other balances)
we can expect bigger previews like we had them in FFXI as soon SE get's the job done on fixing FFXIV up.
untill then it'll stay to a few pictures, dev notes/posts.