Messages hidden within dots and dashes is still used by some some HAM operators, and could be sent via Part 15 low power, perhaps to contain your station I.D.
I was reading the article and I liked the fade out of the print half way through and if I wanted to see more I had to subscribe and create an account and of course pay, to which I just muttered *bleep*you! But they were nice to offer me a free trial.
Yes we could use Morse code for announcements on part 15 stations but I don't think anyone could understand Morse code language and or translate it. I think Morse code was created to be a distress signal done by flashing a light or making a sound in a certain pattern that could be understood by someone from far away. Before telephones someone could message someone else with a telegraph machine.
Before it was possible to speak by voice over long distance wire it was known how to send electrical pulses and the telegraph was born. Railroads depended heavily on instant telegraphy to manage train routes before 2-way radio was possible. People could drop by a telegraph office and send a telegram to friends and relatives.
From the earliest days of Radio Phvern I've used "CW" (carrier wave) in my station ID. In the past I've had at least one foreign language ID, usually Spanish.