I have a feeling that just a 5800 will be released to slot in what would otherwise be 5700 and X space. (basically: why do another tier of 8 cores?)
the way the 6 core performs right now, in certain test cases better than it's 8 and 12 core big brothers, there just doesn't seem to be room for 3-4 8 core SKUs, in reasonable performance gap and price point measures. Maybe a limited edition with a silver stamp to denote crummy dies that they want to package as the "value" AMD 8 core Zen 3, end of year?
Or, actually! those might just be OEM-only chips. You'll see them on HP: "Bleeding Edge, Zen3 5700 XS edition! Exclusive!" It will exist, on stickers for machines in Best Buy, but you can't get one off the shelf? (of call it 5800S, limit to OEM, when it is the spiritual heir to the x700 tier, RIP)