There is no doubt that the latest Ryzen Epyc processors are clear winners in every aspect. More cores, more speed, lower power consumption, more memory channels, more pci-e channels, faster pci-e channels, cheaper prices, better motherboard support, more longevity, safer, more future proof, more forward looking, can scale easily, etc...
There is literally zero reason to purchase an Intel server cpu right now, unless you are in a niche low level server market that needs very low power consumption processors that are also very slow, but when AMD releases the new Threadripper processors they will undoubtedly eat into that space as well, with 16 to 32 core threadrippers at low power consumption and faster speeds than intel counterparts.
The only thing that needs to happen is for game companies to start better optimizing for more cores and Ryzen cpu's in order for AMD to win in all aspects. We actually see it in few games where 3900x wins against 9900k, even tying with a 5GHz oc'd 9900k.
Lisa Su confirmed that next gen Ryzen is finished, so Zen 3 is ready, hopefully we see better latency reduction in memory, even 5-6% percent improvement there would be huge, if they can further optimize their scheduler, hopefully with a more mature 7nm or 6nm process next year they can squeeze out 300-400mhz more and that could give them further 4-5% IPC improvements.
TSMC announced their 6nm which is based on their first gen 7nm technology, it allows for about 15% better performance or power consumption and is fully compatible with 7nm and all of the tools and packaging current 7nm uses.
Their 7nm+ is actually more advanced than 6nm, but it would also require new development and tools to use it. So my bet is that AMD is going to use 6nm next year, maybe even test it out with Threadripper as I believe they will release those processors in Q1 2020, and then roll it out completely with their Zen 3, probably sometime in Q3 2020.
Then jump to TSMC's 5nm process which TSMC's CEO said would be their long term process, one that they would use for a longer period, as he expects improvements with lower process nodes to be smaller and way more difficult.
So 2019 use 7nm for all their products, continue using it through 2020, maybe test 6nm with Threadripper in Q1 2020, otherwise introduce 6nm with Zen 3 in H2 2020, move to 5nm when it's ready, most likely H2 2021.