I listened to some of his lectures a few weeks ago as the situation was becoming more visible, and they left me unimpressed. That his lectures have many more views on social media than those of other scholars discussing the same subject ought to raise eyebrows. "The medium is the message."
With that said, if our detoriating relations with Russia ever result in a nuclear war, he will have some claim to vindication. His argument relies on the implication that placating Russia is the most reliable strategy for preventing global catastrophe. Admittedly, that is a good-faith interpretation of his views that many of those now making this argument do not deserve.
Blanche Carte Appeasement is never the answer. Period.