Essentially, you will get Piety options related to stuff an Immaculate Monk would consider a good idea, public works--public schooling, basic literacy, and making sure you have a good and efficient calendar.
It also means that you won't get a lot of the more animistic deal stuff with particular Gods, because you're really not supposed to do that sort of thing. They're also approaching this from the Immaculate Order's standpoint--which is "Gods are meant to do their jobs, and not to make themselves known", and "The Dragon Blooded are the pinnacle of enlightenment prior to becoming one with the Elemental Dragons, and following their commands cannot draw you further away from enlightenment".
It's not... You know, inherently bad or wrong--it largely works, but it does tend to ignore the advantages of having personal relationships with the local gods, since they're not supposed to get more credit then a few nods on certain calendar days. It does guarantee a basic standard of worship for most Gods, but nothing above and beyond that encourages them to put in overtime.
Frankly, the setup in Yilali is Mostly compliant, as a lot of the small gods still get a take in the local tithes, so if you take the Piety Advisor, they're not going to run out and start burning things down because HERESY, but you won't get new options that directly try to get special favours from local spirits, just stuff that keeps them getting angry and showing it.
