The symbol seems harmless enough, but if I open an old project just to print off a copy, I probably don’t want the copyright year to be updated. On the other hand if I start working on a “new” project in one year and it continues to the next, I probably do want it to be updated.
Controlling an “automatic” token for the year seems just as much bother as typing four digits.
When I used Sibelius in the past, there was a context menu for text entries, depending on the kind of text I wanted to create. (right click)
Next to the Copyright sign, there are a few other letters and signs, which would be quite nice to have in a quick way (e.g. “ù” for “più”). Perhaps something like this would be an even better solution.
Having a button or context menu to add the copyright symbol would seem most convenient, but I have no problem typing ALT+0169 when I need the symbol (and I must need it enough to have memorized the code. 
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