Thanks for raising this up.
That’s a fair point, we have not generated a changelog since we’ve automated our release process, but I’m fixing this today.
I’m creating a changelog for this version and including the changelog as a step on the release script.
You can upgrade safely to v4, it’s not a breaking change.
The biggest change is that plugin does not connect to the API using an access-token and a Facebook App anymore, instead it uses the new meta tag “ia-markup” to tell Facebook’s scrapper to ingest the articles. The only required field on the settings now is the Facebook Page ID, which you already have saved if you use v3.
Thanks for the feedback!