Yes. Back in the days when the Japanese phone industry was an island unto itself, they had a 16-bit custom character encoding and not enough common characters to fill it, so various manufacturers stuck UI icons and other assorted pictures in there. A decade or so later, when Apple and Google wanted a piece of the market, for interoperability reasons they had to support all the same glyphs. Since both iOS and Android are unicode-based, the easiest thing was to get them officially added to Unicode.

There's already stuff like Linear B and even alchemical symbols in Unicode, so it's not not just for current writing systems. Anyway, four-byte characters give you plenty of room to cram in whatever junk seems useful at the time. It's big enough to handle a little scope creep.