I think the rate used to introduce things is quite correct, as the newbie already have to deal with a lot of new stuff, and adding more may be overwhelming.
The main story itself is introduced gradually, with more deep as long as you progress.
Throwing it all at start, is typical of f2p, that needs keep immediate attention of player and make him urges to use cash shop. Here is a long term experience, to let you want progress further into story, to see what happens then. It happened sometime I gone sleep later, because I wanted to see what happened after some points of the story. Don't remember other games that had let me do same thing.