They are trying to group Velious patches by month, but time constraints and real life creep in and cause delays. Kunark lasted for over 4 years. There was a long gap between kunark and epics and veeshans peak. This wiki page collects the differences between the live timeline and the p99 releases. Considering this is free and done in people's spare time, it is amazing it has even made it this far and lasted this long.
http://wiki.project1999.com/Players:EQLive_Timeline
Ideally, the devs would like expansions and patches to follow the live timeline. If/when a new server comes out.