Considering how many times author referenced BlueOak license, it seems like he had a license to promote.
No, MIT license is not deprecated. Ton of FOSS projects use it and will continue to use it.
OK, well, if that's not good enough for you: The other two Blue Oak board members listed at that site — Heather Meeker and Luis Villa — both have serious reputations in this field.
(Disclosure: Kyle Mitchell is a friend, and both a good lawyer and a good guy.)