I cannot test the latest version of WPML as I am not a customer ;-)
Polylang *is* compliant with EU cookie law (it's important for me as I am European). Just took this quote in the link you provide:
Some cookies can be exempted from informed consent under certain conditions if they are not used for additional purposes. These cookies include cookies used to keep track of a user’s input when filling online forms or as a shopping card, also known as session-id cookies, multimedia player session cookies and user interface customisation cookies, eg language preference cookies to remember the language selected by the user.
However I will apply your patch in the next version (1.0.2) ... although you must be aware that some functionnalities will break.