AMD is yet to officially detail Cezanne Zen 3 desktop APUs, but we have been seeing several instances of the Ryzen 7 5700G and Ryzen 3 5300G showing up in benchmark sites and even on eBay. The latest such leak comes via a UserBenchmark listing of an upcoming HP EliteDesk 805 G8 mini PC discovered by known leaker @TUM_APISAK on Twitter.
The UserBenchmark listing only shows the OPN code of the APU, which is an AMD Engineering Sample 100-000000263-50_Y. So far, we have come across OPN codes 100-000000262-30_Y and 100-000000263-30_Y, which correspond to the Ryzen 3 5300G and the Ryzen 7 5700G, respectively. Therefore, 100-000000263-50_Y could likely refer to a Pro APU. i.e. the Ryzen 7 Pro 5750G. It was originally thought to be a Ryzen 7 5800G, but such an APU is not known to be in development so far.
HP did launch an EliteDesk 805 G6 mini PC aimed at businesses last year. The EliteDesk 805 G6 is powered by the Ryzen Renoir APUs such as the Ryzen 7 Pro 4750G, and it also offered an option of a discrete NVIDIA GeForce GTX 1660 Ti GPU. Thus, the probability of the upcoming EliteDesk 805 G8 featuring a Ryzen 7 Pro 5750G APU is rather high.
Since the benchmark still reports that the APU is an engineering sample, the specifications may not be final. Nevertheless, we do see an 8C/16T part clocking at 3.7 GHz base and up to 4.4 GHz boost. UserBenchmark also reports a Radeon RX Vega 8 as the iGPU, but it is not clear what would be HP's choice for a discrete GPU this time around. It could be an RTX 3050, but that's just speculation for now.