You always have to take rumor with a grain of salt but I do recall hearing from the usual suspects that there would be a 10 core 20 thread and 14 core 28 thread Threadripper.
I was therefore mistaken assuming there would be an entry level 10 core 20 thread Threadripper rather then a mainstream overlapping 8 core 16 thread part.
So there is some disappointment there for me but the entry level Threadripper is still a noteworthy part IMO. I'm still not convinced that it won't drop in price like the RyZen 1800X though,.....
I think right now they are just mirroring the Ryzen configurations.
1900X = 2x Ryzen 4-core dies
1920X = 2x Ryzen 6-Core dies
1950X = 2x Ryzen 8-Core dies
Probably to make binning dies easier. They aren't testing for 5 and 7 core dies right now, because that would add too much time to the binning process.
And I think the 1900X is a good entry level CPU simply because of the staying power of the sTR4 socket. It is my theory that AMD can enable more than 16 cores if they want, using the extra dies.