Although it was an engineering sample which was not at its final clocks, the 8-core/16-thread chip previewed by AMD at the CES 2019 keynote traded blows with Intel's Core i9-9900K, and it showed some impressive power efficiency as well.
While AMD was only showing the 8-core/16-thread sample, the package held by Dr. Lisa Su, AMD CEO, at the keynote clearly shows there is room for a second 8-core chiplet on the package. In an interview with Engadget.com, Dr. Su confirmed that there is extra room on the package, allowing AMD to put more than eight cores, at least if it deems it viable and necessary.
Hopefully, AMD will give out a bit more details as we draw closer to the announced middle of the year launch date.