I have no idea why people would even want Ryzen Macs...
People don't really want Ryzen iMac per se -- they want an improved iMac with more cores and better performance. Since Intel has been unable to produce a mainstream CPU with > 4 cores, Ryzen might be one way to get that.
Intel's laggardly development of > 4 core mainstream CPUs is remarkably similar to their refusal to develop a 64-bit x86 instruction set in the late 1990s. This was an artificial constraint designed as a marketing method to bolster their upcoming 64-bit Itanium CPU.
Back then AMD stepped in and developed 64-bit x86 instructions, and those 64-bit AMD CPUs proliferated so rapidly that by the time Intel finally realized their error, it was too late. For Intel to add 64-bit instructions to their own x86 CPUs, they humiliatingly had to license those from AMD.
In the succeeding years, Intel with their huge fabrication and R&D budget pulled far ahead. However then a developmental malaise set in, and Intel CPU development has stagnated somewhat. Part of this is due to approaching architectural and process limits, but part is intentional. If tiny AMD can develop an 8-core mainstream CPU with such good performance, obviously Intel could have done this long ago.
AMD is not stopping there -- they may have a 16-core Ryzen by end of this year. Intel would greatly prefer selling high-margin Xeon CPUs which at a given clock rate and core count don't perform any better than an i7. However AMD has forced their hand on this.
I don't really think Apple will make a Ryzen iMac, but consumers win either way. If they make one, good. If they don't but Intel fears they might, this will probably wring concessions from Intel and spur their own development. Either way the market will still be flooded with Ryzen-based Windows PCs, so Intel must act -- regardless of what Apple does.
Re "Can we put AMD/Ryzen rumors to end?", the very name of this website is Mac
Rumors. A key purpose is to discuss speculative or rumored events. If you don't like people doing the very thing the website is named for, maybe you're at the wrong place.