Apple doesn't have the lineup for that. The CPU in the Mac Pro isn't the same silicon as the CPU in the Mini. It has more cores, bigger caches, more memory channels. It's not just the same chip binned differently.
In theory they could offer the Mini with eighteen different CPU options, but that's not really their style.
One question is whether they'll go down the chiplet route for higher end CPUs, then they can share a single die, binned differently, across more of their range, and just bundle them into different MCMs.
The 3990X costs more than ten times as much as the 3700X. It has eight times more cores. On anything threaded it smashes the 3700X. On anything not threaded it... doesn't. In many cases it loses slightly because the turbo clock is lower.
It basically means that the processor with the best single thread performance is somewhere in the lower half of your lineup and everything above it is just more chiplets with more cores. That's perfectly reasonable for servers and high end workstations that scale with threads. I'm not sure how interesting it is for laptops. Notice that AMD's laptop processors don't use chiplets.
Even the highest core count Threadrippers have decent single thread performance. The Epyc lineup has much lower single core performance and that may make it less useful for desktop workloads.
AFAIK the AMD distinction is currently that APUs (mobile or desktop) don't use chiplets.
On the whole my guess would be that we have the iPad Pro and MacBook Air using the same SoC, the MacBook Pro doing… something (it'll still need integrated graphics, but do they really sell enough to justify a new die? OTOH they do make a die specifically for the iPad Pro, and I'd guess it's lowest-selling iOS device v. highest-selling macOS device, and idk how numbers compare!), and the iMac (Pro)/Mac Pro using chiplets.
Don't worry, apple already tiers most of it's hardware by soldering in the ram / storage & charging an offensive, obviously price gouging amount to upgrade - even though the maximum spec has a base cost to them of 1/4 to 1/6 of what they charge FOR AN UPGRADE.
The Mac line will start to look like the iOS line very quickly. Binning will be important and you'll likely see processor generations synchronized across the entire product base.
I've been thinking about this. I can't see Apple realistically being able to produce multiple variants (phone, tablet, laptop, speaker, tv) of multiple elements (cpu, gpu, neural accelerator, wireless/network, etc) packaged up on an annual cadence.
The silicon team is going to be very busy: they've got the A-series, S-series, T-series, H-series, W-series, and U-series chips to pump out on a regular roadmap.
The A-series (CPU / GPU / Neural accelerator) is the major work. It gets an annual revision, which probably means at least two teams in parallel?
The A-series X and Z variants seem to be kicked out roughly every second A-series generation, and power the iPads. The S-series seems to get a roughly annual revision, but it's a much smaller change than the main A-series.
I could see the Mac chips on a 2-year cycle, perhaps alternating with the iPad, or perhaps even trailing the iPads by 6 months?
The iOS line looks like the low end device using last year's chip. How does binning help with that? Are they going to stockpile all the low quality chips for two years before you start putting them in the low end devices? Wouldn't that make the performance unusually bad, because it's the older chip and the lower quality silicon?
In theory they could offer the Mini with eighteen different CPU options, but that's not really their style.