Thanks for the report.
It is not broken. The docs can be clearer on the fact the is_quoted () and is_binary only return usable values when passing the keep_meta_info as a true value:
use Text::CSV;
my $csv = Text::CSV->new ({ sep_char => ' ', keep_meta_info => 1 });
$csv->parse (q{"a"});
say $csv->is_quoted (0) ? "true" : "false";
I have changed that in the docs for Text::CSV_XS, which eventually might end up in the docs for Text::CSV.