There are still a  few things pending in the ZEN3 line of products, APUs for example. Among the line, a Ryzen 5 5300G, and that one has been sighted as an engineering sample, and tested. 

The proc has actually been listed on eBay and carries hardware ID 100-000000262-30_Y, the proc was already sold, however, benchmarks have been posted. To prove that this engineering sample is indeed a Cezanne line APU, seller Hugohk posted a series of snapshots and even a video showing the processor in operation. The seller also provided some details on the performance of the Ryzen 3 5300G, compared to other processors on the market. The Ryzen 3 5300G reportedly performs well in Cinebench R15 and R20, scoring higher than other processors such as the Ryzen 3 PRO 4350G. In order to test the games, Hugohk had to use unofficial drivers in order to use the processor's integrated GPU. As a result, in the two titles tested, the APU performed satisfactorily, hitting 95 FPS with "low" graphics in Battlefield 4  at 1080p resolution. With the low availability of graphics cards in the market, and the problem of price premiums, the Ryzen 3 5300G could hit the market as a cheap alternative for those looking to play on PC.

The 5300G would get four cores and eight threads with a dormant 3.5 GHz base clock, boost/turbo frequencies however are unknown, Check it out:

AMD Ryzen 5 5300G Engineering Sample Sold on Ebay and Benchmarked