I get why people are focusing on this bad actor. But the question that interests me more: how many other apparent individuals fit the profile that this person presented before caught?
Are you referencing the '-unsafe' suffix in the second link? That is not something to worry about.
This is from Gnulib, which is used by Gettext and other GNU projects. Using 'setlocale (0, NULL)' is not thread-safe on all platforms. Gnulib has modules to work around this, but not all projects want the extra locking. Hence the name '-unsafe'. :)