and some people don't think Zen has taped out, an x86 CPU needs 18+ months from tape out to availability. Zen CPU taped out a good long while ago, mid last year at the latest, quite possibly early Q1. Zen APU may have taped out a little later but that will have taped out also by now.
x86 takes more validation and thus way way more time from tape out to release, than pretty much all other chips. Anything that slots into an existing platform needs to only conform to that one standard. Anything that doesn't slot into an existing platform, like a new phone, only has to make that one device work with that chip. An actual basis for a platform, new cpu, new chipset, has to make sure it works perfectly to EVERY standard. It has to work perfectly with pci, pci-e, sata, ddr3/4, gpus, outputs. Every audio chip maker needs time to make a new audio chip that works with the new chipset(not necessarily difficult or a lot of work, usually a new revisions of a existing chip), every nic that might be on a mobo needs to be validated to work on the new mobos. Platforms take an age in industry terms, in general this validation only takes more time and gets more complex the longer the industry has been around. It's one reason why getting rid of obsolete things like PCI is important as it means a whole lot less crap you have to make sure works.