I don’t think there is a typographical reason to include it, but if you are a Mac/Apple fan you might want to add it.
I’m not sure, but it is likely the Apple logo shown in the main menu on a Mac comes from the system font.
Maybe you should think about adding an Easter Egg inside your fonts
The Hoefler Type Foundry includes this glyph (named Apple, code point $F8FF) :
