The vast, vast majority of people who present as male wish to be referred to as "he". Many of them would be offended or confused if you used "they" as a term of reference. Many listeners would also be confused if you referred to a person who appears to be a typical male as a "they".
If 99% of men go by "he", why should we use "they" as a term of reference by default? This is the tail wagging the dog, to say the least.
1: the list also says we are not to refer to "preferred pronouns" anymore. They are just "pronouns" now.