When the logic board fails, data recovery is seemingly not possible on the 2018 MacBook Pro.
Apple has a special tool for 2016 and 2017 MacBook Pro models with Touch Bar that allows Apple employees at Genius bars or Authorized Service Providers to recover data when the logic board of the MacBook fails. It appears to be the case this special tool won't work with the 2018 MacBook Pro models.
An alternative way to recover data is by using the Thunderbolt 3 ports on the MacBook to transfer the data to another Mac, by booting the system in Target Disk Mode, which is "useful when you need to move files quickly between computers, or get files from a Mac that doesn't have a working display."
The data recovery port was probably removed because Apple added the Apple T2 chip to the new MacBook Pro models, which provides hardware encryption for the SSD storage.