Interesting tip. The QuickType solution doesn’t seem to work for me. This a setting of some kind? Seems to me, the (c), (r), and TM shortcuts used to work, at least on the Mac. But no more.

The emoji solution always works. Copy and paste works too, especially if I do the copy on my Mac and paste on my iOS device.

UPDATE: Thanks to a big wave of Twitter response, I can see that there are some iOS installs with default text substitutions for (c), etc. But others do not have these substitutions. Perhaps they were replaced? Regardless, you can add them back in via Settings > General > Keyboards > Text Replacement.