We'll know for sure when the product is actually out and we have independent benchmarks, but at this point you're just making things up and stating them as facts.
That aside Epyc was already ahead on real high-end workloads like povray or NAMD ( http://www.ks.uiuc.edu/Research/namd/ ). Epyc also puts up top numbers on compilation performance and OpenSSL. So it already isn't as black & white as you're pretending anyway. MySQL/DMBS is not the only server workload that exists, even though it may be the only workload you specifically care about.
And those players have already announced AMD is being added to their offerings: https://aws.amazon.com/ec2/amd/
DBMSs are normally IO constrained or memory constrained, or lack-of-index index constrained or query-plan-gone-mental-from-cardinality-misestimation constrained, or others. It's very unusual IME to find one that is CPU constrained. Bringing up DBs in this context is peculiar to say the least.
I've literally just lost 20 hours trying to debug a query that intermittently ran many times too slow. It was a memory misconfiguration. Extra CPU is at best a bandage over these kinds of problems, at worst, just wasted.