While I won't prevent later-generation Pokemon from being documented on the wiki, I'm personally averting to wiki work that will be more immediately resourceful to wiki users--data that is relevant to PWO's current gameplay state, to which the wiki is still considerably incomplete in. I expect 5th-generation, and onwards, Pokemon to be implemented in one day, but as of now, they are immaterial; their entries, at the biggest stretch of their faculty, would be rather vastly watered-down Bulbapedia pages, information-wise.
Moreover, not all 4th-generation Pokemon have wiki entries yet--we've only been adding new entries slowly as more 4th-generation Pokemon have made their release in-game. If we want to expand on the library of Pokemon pages on PWO's wiki, adding in the remainder of the 4th-generation pages would be preferable before we advance to later-generation Pokemon.
While not all 4th-generation Pokemon have been fully integrated in-game yet, they do exist in the database, thus their rudimentary information can be accurately added in at this time (PWO-specific data, such as the catch rate, base-experience values, and so forth); their locational information is mainly what it's needed to be added later.
5th-generation Pokemon, on the other hand, aren't databased in yet, thus we're still lacking needed information on them. Which information would you be the most interested in seeing for 5th-generation Pokemon on PWO's wiki at this time, even if they aren't released in-game yet?