twenty fifteen theme removes shortcode notation

Hi,

Curious to see that the twenty fifteen theme (unlike any other I’ve come across) removes shortcodes from the side menu.

I’m particularly referring to the new social icons integrated within the side menu. And even more specifically if an email address is entered as a shortcode eg [myemail] the brackets get stripped.

Surely shortcodes are an inherent part of WP and should not get interpreted in any other way other than for use by plugins or is there a way around so the community can use?

Tks