If you're an iMac Pro user, you should be receiving a survey from Apple asking you about your use of the various features that accompany the device on the hardware front.
The survey includes questions about which of its features you use most, asking users to pinpoint the ones that could use some improvement and the ones that they already find themselves pleased with. It would appear that through some of the questions - namely, the ones that question users over their decision to buy their iMac Pro over other Macs and PCs - Apple is trying to gain a better understanding of the demographic it is catering to.
Given Apple has a dedicated "Pro-Workflow Team" tasked with tailoring its computers for professional users, it is possible that this very team is responsible for the survey's circulation.
One could also infer that Apple is trying to not repeat the mistakes it made with its original trashcan-esque Mac Pro, a product that Craig Federighi himself admitted could have been a lot better designed for its target market of power-users. A new Mac Pro is in the works for a reported 2019 release, and Apple is perhaps also attempting to better distinguish this upcoming device from the iMac Pro through the questions it has asked here.