I've never been charged for a mall toilet in Europe. But hey, that's the problem with saying "Europe". I can tick off maybe a copule dozen malls in maybe three or four countries, so we only have like twenty or thirty countries left to verify, assuming the practice is set at the national level and not regional.
In my mind this was a German thing that people kept saying was a European thing, but I haven't peed in enough public places in Germany to tell you.