The service manual for the Dell XPS 15 9570 has been posted online and it looks like the notebook will sport a similar heatsink design with 2 heat pipes as its predecessor. This raises concerns about the possible throttling issues as the previous XPS 15 9560 had to be undervolted and thermal pads applied to the VRMs in order to prevent performance drops due to thermal throttling and power limits.
https://www.notebookcheck.net/The-Dell-XPS-15-9570-might-inherit-the-same-throttling-issues-as-its-predecessor.302960.0.html