An engineering sample of what seems to be an AMD Ryzen 7 5700G Cezanne Zen 3 APU has leaked on Chinese site QQ along with some initial CPU-Z numbers. These numbers show the Ryzen 7 5700G ES displaying considerable gains in single and multi-thread scores over the Ryzen 7 3700X and the Ryzen 7 4700G.
https://www.notebookcheck.net/AMD-Ryzen-7-5700G-Cezanne-Zen-3-desktop-APU-ES-leaks-shows-decent-leads-over-the-Ryzen-7-3700X-and-Ryzen-7-4700G-in-single-and-multi-thread-CPU-Z-scores.514102.0.html