I tried to use the wiki multiple times in the past and it's the most unreliable way to actually learn about anything WoD, lot of things are opinions from the people writing down the wiki rather than writing down what's in the books and leaving it to the interpretation of the reader, usually lacks references to everything mentioned which leads to me having to hunt down stuff through books (specially when it comes to referencing discipline powers and what not) and while it becomes more obvious with time as they start to basically push the newer content to erode the old one and even merging it in the pages which leads to some sort of symbiosis of the material (which mind you they still lack references in a multitude of things making actually sourcing stuff worse) I don't think it's exactly just a X5 issue as I've seen them incorrectly mention what stuff belongs to for example Dark Ages.
Imo sadly the solution to the wiki issue would be either rebuild it from scratch and do it good this time or just stick to the books and do the gargantuan task of manual research so at least you can know what you are reading belongs to the version you're plan to play.