I don't think that's the consensus. Even if it were the consensus, the I doubt the people making the argument would disagree that the Anatolian languages are closely related to the Indo-European languages. The grammar is classic Indo-European, with 7-9 cases depending on the period. The vocabulary has a lot of cognates with Indo-European languages. The only things that really distinguish Hittite from Indo-European languages are the system of enclitics and grammatical gender based on animacy rather than the usual masculine/feminine/neuter.