An exact launch schedule is still not known. There are some whispers about a CES 2022 announcement but it could also be one quarter earlier or later.
AMD Rembrandt might be announced at CES 2022. This expo is where AMD introduced its Ryzen 4000 Renoir and Ryzen 5000 Cezanne series. The latter was introduced alongside GeForce RTX 30 GPUs by NVIDIA. One year later it is likely that NVIDIA will be refreshing its mobile lineup with the GA103-based SUPER series as well. It seems to be perfect timing to introduce Rembrandt. However, other leakers are so convinced about the possible CES 2022 announcement. Either late Q4 2021 or Q1/Q2 2022 are mentioned.The exact launch date of the Zen 3-based desktop processors with 3D Vertical Cache is also still a mystery.