VideoCardz spotted evidence of the existence of the AMD Radeon Picasso. According to a previously leaked roadmap, Picasso is a Raven Ridge successor. Other than a device ID, there are no further details at the moment.
Interestingly, Radeon Picasso has been discovered by the 3rd software recently and is currently listed at UserBenchmark database under 15D8 Device ID. Sadly, no benchmark results are available right now, but that ID is enough of a reason to consider this leak plausible. Current Raven Ridge APUs are carrying 15DD ID.
Picasso is said to be an improvement of Raven Ridge, it's expected in 2019 and promises better power/performance. It will have Socket AM4 desktop variants as well as Socket FP5 laptop editions.