Sony has yet to talk much about how we'll get to play older games on the PlayStation 5, but now they've at least reiterated just how many PlayStation 4 accessories the upcoming console will support.
Isabelle Tomatis has specified that the PlayStation 5 will support the following PS4 accessories:
The DualShock 4 and other PlayStation officially licensed third-party controllers
Officially licensed specialty simulator peripherals like racing wheels and flight sticks
The Platinum and Gold Wireless Headsets, as well as third-party headsets that connect via USB port or audio jacks
The PS Move Motion Controllers and the PlayStation VR Aim Controller
She also specifies that the DualShock 4 can only be used to play PS4 games and that those who own a PlayStation Camera will get an adaptor at no additional cost to make it usable on the PS5. We'll learn more about how the latter will work at a later date.