It seems there is news, at some point schematics for the Fairphone 4 became available.
I discovered this from a recent Louis Rossmann video:
Indeed, they can be found on Fairphone’s official site at https://www.fairphone.com/wp-content/uploads/2022/09/FP4_Information-for-repairers-and-recyclers.pdf
The upload date in the link appears to indicate September 2022. 
Has this ever happened for the Fairphone 3 and 2?