Maybe it will have some meaning in the future which will break my existing code.

Extremely unlikely. Perl5 has never introduced a regexp change that suddenly made a non-special character (in a legal regexp) into a special character. And I doubt pre-perl5 ever did. Every new regexp feature introduced is carefully designed to use syntax that's currently invalid. With one exception: backslashed letters. It's documented that backslashed letters that currently do not have a special meaning may have in the future. But this warns.

A > currently does not have a special meaning, it's unlikely to ever will.