After the Facebook–Cambridge Analytica data scandal, Facebook has started to implement drastic changes to the platform. There have been overnight breaking changes in a short period. Now, after the F8 event, with the release of Graph API v3 and the opening of the new App Review process, we can consider that most of the new model is ready and we can start rolling out the news to our software packages.
The OG plugin method still works. However, given the direction where Facebook is going, it seems that they are focusing all efforts and managing tools on the Business Manager. So, at some point, it could become "the only way" to do it.
So, to be on the safe side, we recommend starting using the Business Manager.