The biggest problem with AMD platform and Thunderbolt is that the cost of the chipset is between 6 and 8 USD, but overall cost add-on to the motherboard is 20-25$. And AMD wanted to have the most, but not for the sake of more expensive platform than Intel.
On the other hand, prepare, that Zen+ Motherboards might have Thunderbolt native. There will be new models released in upcoming years and are already developed. I heard about MSI model with TB3 or 4, but it can just be a rumor.
Like I have said before many times. AMD's marketing team is rubbish. They have genuinely great hardware, that offers phenomenal value, and they should be shouting, and screaming to the world about this, pre-release, yet they have shut up their mouths. Well, they want to hardware speak for itself, but... it not always sell the hardware.
This is the best example what differs AMD from Nvidia: AMD is run by Engineers. Nvidia is run by people from Marketing department. Intel is run by technology.
Nvidia and Intel sell the most hardware, regardless of how good or bad it is. AMD sells small amounts of hardware regardless of how good or bad it is.