How to setup Dual Apple Thunderbolt Display 27 inch with Thunderbolt 3 MacBook Pro and Ethernet
The product page indicates that you CAN use the adapter for the display.


  In addition, it can be used to connect Thunderbolt-enabled displays — such as the Apple Thunderbolt Display and LG Thunderbolt 2 displays — to any of the Thunderbolt 3 (USB-C) ports on your MacBook Pro.


Please note the distinction between Thunderbolt and mini-DisplayPort. The Apple 27" Thunderbolt Display ISN'T primarily a display. It's actually a Thunderbolt-connected hub with a built-in display. Why is this distinction important? Because it means that the data traveling from the computer is being transmitted via Thunderbolt, not DisplayPort protocols. While it is true that you wouldn't be able to use the Thunderbolt 2/3 adapter for a mini-DisplayPort monitor, using it to connect your Thunderbolt monitors WILL work. According to the products webpage:


  This adapter does not support DisplayPort displays like the Apple LED Cinema Display or third-party DisplayPort and Mini DisplayPort displays


Source: Apple Product page

Edit: I assume you mean the 2016 MBP, as no 2017 model has been released as of this question.