Apple recently updated the 27" iMac to include a 10th gen Intel CPU and SSD storage (
https://www.apple.com/shop/buy-mac/imac/27-inch). I don't see Apple in its current form releasing a machine with a sub-6 month shelf life, which is what your scenario would require. I know people point to the PowerPC - Intel transition as an example of Apple doing just that, but Apple as a company is in a significantly different place in 2020 than it was in 2005-6. That's not thinking like an "old PC window clone head", that's looking at how the company and the market has changed in the last 15 years. In fact, replacing a model so soon after release as you "predict" is more representative of the PC model, as PC manufacturers usually refresh their lineups three times a year. As far as the DTK is concerned, the benchmarks are meaningless, since that is a unit meant for development of AS applications rather than actual production hardware of the AS lineup of Macs.
Where Apple needs to compete head to head with Intel and AMD up front is not in the high end - they need to go head to head with the Core i3/i5 notebooks and provide at a minimum equivalent performance with significantly increased battery life. If the new AS Macs get improved performance and battery life from the jump, that positions Apple better going forward. I will seriously consider replacing my i3 MBA with an AS Mac if the performance is equal to or greater to this machine with better battery life. That is the combination that is going to hit Intel and AMD the hardest. Look at Intel's 11th gen presentation, where the only processors they are actually replacing are the Y and U mobile SKUs - not even the slightest mention of desktop parts. That's because mobility is the driving force in the computer industry, so performance per watt (although the average user doesn't use that term) and battery life are driving the purchasing decisions of many businesses and individuals.
Intel is scrambling right now because AMD just formally announced their 5th gen Ryzen parts, in which they were able to get big boosts in performance without increasing the CPU power draw (still 105W). There are two reasons for this: AMDs move to the 7nm process (which puts them approximately 2 years ahead of Intel in that regard), and the adoption of "Big Navi" and the Zen 3 core for their processors. Meanwhile, Intel is releasing spec bumps as new processor generations while misleading their audience by only comparing their new iGPU to 3-year old AMD iGPUs and workstation class nVidia cards (MX250, not even the current MX350). In order to regain some of their clout, Intel would have to either take massive risks (which its risk-adverse business model doesn't allow) or bite the bullet and outsource fabrication to TSMC or a similar company who has already solved the yield issues that have bottlenecked Intel for the last few years. Microsoft pledging to improve Windows on ARM is another shot across Intel's brow, as moving away from x86 would by necessity further shrink Intel's market share and revenue streams.