I don't want to derail the AMD 390 thread so I'm writing this here:
https://forum.beyond3d.com/posts/1831601/
AMD writes:
I guess what stuck out was the word discrete for me, since if they were just the first full DX12 implementation, they would just say it and not tack on discrete. This leads me to believe,unless they had a marketing oopsie, that the first fully DX12 implemented GPU could very well be the XBO like many rumours have suggested and not suggested.
Since XBO is SOC, the statement would be still true, that fact that it's tacked onto the statement could be some sort of admission that it wasn't first across the entire market.
Having said that, I guess the case isn't closed on the matter