I would take that etymology with a huge pinch of salt, as it involves both an unusual use of bang to mean # and then a reversal of the order the symbols appear

I would take that etymology with a huge pinch of salt, as it involves both an unusual use of bang to mean # and then a reversal of the order the symbols appear in. The other suggestion I've seen is that it is a contraction of sharp-bang or shell-bang seems like far less of a stretch.