Hello Bernhard,
It’s not an issue of rolling releases.
Sure - rolling releases usually have the latest version of gnuPG available, so if it is a regression we will see it first.
I assume you configured the log socket yourselves, in that case its a misconfiguration by the user. It could theoretically be a misconfiguration in the global config files by the maintainers of these distributions, too, but I guess then we would get more questions regarding this.
I have not touched this at all, but opened a bug: 1226912 – gnupg problem with socket connection