See <https://bugzilla.wikimedia.org/show_bug.cgi?id=42893#c1>
Nobody has been working on this for years and nobody plans to work on
it. Adopting the new log system is not hard in itself, but it requires a
deep knowledge of the log type being converted and/or a lot of research.
So, extremely boring + left to volunteers + high risk of breakage =
almost never going to happen.
Every now and then someone, while refactoring things, also converts a
log from old to new format.
Nemo