This article does a reasonable job of explaining how USB-C, Thunderbolt and DisplayPort coexist and interplay on the same physical connector.

Explaining Thunderbolt 3, USB-C, and Everything In Between

Personally, I have ordered a new 2016 MacBook Pro 15" with intention of connecting three external 4K displays, plus wired Ethernet and a bunch of legacy USB things. Currently hunting for a Thunderbolt 3 dock that ticks all my feature desires.