These third party blocks have been in place since the first Thunderbolt 3 Mac launched. They didn't start blocking anything in particular 'shortly' before they

These third party blocks have been in place since the first Thunderbolt 3 Mac launched. They didn't start blocking anything in particular 'shortly' before they announced this dev kit at all. These third party devices that Apple blocked were not just enclosures, there were other TB3 devices (e.g. dual display adapters) that Apple to this day have not announced or endorsed a competitor to, and in fact those same companies (e.g. StarTech) then released Mac compatible versions, which suggests Apple were just enforcing a standard that they wanted OEMs to meet before allowing them to work by default. The blocks have been found to be based on an earlier chipset version, and that devices made using later versions of the TB3 chipset work just fine. This is what a peripheral manufacturer said (Plugable): The version of OS X on the new MacBook Pros (late 2016) will not work with existing Thunderbolt 3 docks and adapters that were certified for Windows prior to the release of the MacBook Pro. These existing devices use first generation of TI USB-C chipset (TPS65982) in combination with Intel’s Thunderbolt 3 chipset (Alpine Ridge). Apple requires the 2nd generation TPS65983 chipset for peripherals to be compatible. Certification of solutions across different device types is still in-progress for this 2nd generation chipset. From the Plugable product line, our dual display graphics adapters for DisplayPort and HDMI (TBT3-DP2X and TBT3-HDMI2X) are affected… We’ve also postponed our TBT3-UD1 Docking Station to update to the TPS65983 chipset and re-certify to make this docking station MacBook-compatible. Our Flagship TBT3-UDV dock with Power Delivery/Charging was already planned to use the next generation controller chip from TI, and will be compatible with the 2016 Thunderbolt 3 MacBooks. This does still fit with your argument?