[2021] Link / Transfer DbD Steam Acc to PS4 Network

No, as of now it's not possible. Currently cross-progression only exists for Stadia and Steam, Switch will be added soon.

Originally posted by Chippy1979: Thx, and its not on the roadmap? :-(

As of now it cannot be made available on other platforms, but they know it's a community wish and they're trying to make it possible, but there are no guarantees.