You can update directly. And the CC apps allow you to have multiple major versions installed simultaneously. So as I've been using this machine for a while, I've got CS6, CC2014.3, CC2015.?, CC 2018, 2019, and 2020 along with public beta 2020.
As I switch to a new machine shortly, I'll "lose" probably everything earlier than 2019, as that's the earliest one you can currently download.