I'm skeptical Apple's introduction of their high performance CPUs exclusively on a low end device. A super light/ high performance 12ish inch machine seems right up their ally, but they don't want the new CPU associated with being a low-end "Intel Pentium Gold" type device.
There might be a lower end ultra-thin laptop released, but they are going to go big and push out a high performance CPU right out the gate. They didn't launch their 64 bit A series CPU on a secondary device, they won't launch this on a secondary device either.
Edit: Thanks to the replies letting me know that Rosetta is still a thing. I somehow forgot. Updated.
You will be able to run existing MacOS software on the new hardware under emulation. The Dev kits run emulation fairly well on a 2 year old iPad CPU so I would expect whatever new hardware they release will as well.
I’d assume them to do the same: a high end (MBP?) and low end device (MB? MBA?); that’s where ARM will shine first (mobile: battery life; maybe even integrating a modem with esims).
Desktops will follow later.
You can group the Notebook Shipment into a few Categories, $1000+, those are nearly all MacBook. With the remaining going into Gaming Machine ( Which is now being rebranded into Content Creation Machine )
You have the absolute low end, Netbook style that are $300, those are not what Apple targets and they are actually competing with an iPad.
You have vast majority of the Notebook in $300 to $600. Considering the lowest MacBook offering at $699, is just the same play as iPhone SE at $399.
It is just $100 more than the median of average Smartphone selling price, and it would attract enough number jumping to Mac platform all while sucking out the oxygen for the other PC vendors.
If you look at the history of the MacBook and MacBook Air together, it's pretty clear that Apple expected to eliminate the MBA as a product category years ago; to just have "MacBook" and "MacBook Pro" categories. This was probably due to them believing Intel's roadmap for chip releases, such that they thought they'd be able to hit MBA-like performance targets in the MacBook's form-factor. But Intel's roadmap didn't pan out, and so Apple had to turn around and build more MBA-form-factor devices to hit those performance targets. Eventually, the MacBook went so long between releases that they just eliminated it, and redesigned the MBA a bit to cater more to the people who liked the MacBook form-factor (without really making the MBA any lighter, just smaller-seeming.)
All the MBA computers since 2015 "should have been" devices with a MacBook form-factor and MBA-level performance. Right now, that'd mean an ultralight with a CPU matching or surpassing the performance of the https://www.cpubenchmark.net/cpu.php?cpu=Intel+Core+i7-1060N... (which is the highest-specced option for current MBAs.)
Such a computer, if released today, would be impressive, no? It would redefine the MacBook (Air) category to be Apple's primary Mac product line, satisfactory for almost all workloads (in the same way that the iMac has been redefined to be the primary desktop Mac, satisfactory for almost all workloads.) In that world, the MBP would be relegated to halo-product status, akin to the current positioning of the Mac Pro. In Apple Stores, you'd have three differently-sized MacBooks, and then an MBP off in a corner where looking at it for too long summons an Apple Business representative.
I don't see how that's not already "going big" or "making a statement." It'd demonstrate that their Apple Silicon chips can eat Apple's own lunch, with their new mid-range Apple Silicon devices beating their old high-end Intel offerings in price:performance, even before Apple Silicon high-end chips get designed to truly replace them. The Intel MBPs, even brand new, would be immediately branded as a "legacy" category, outmoded even before replacement, only to be purchased if necessary for a specific business use-case.
(Before you suggest: no, I don't think Apple would be Osborning their Intel products if they did this. Businesses and freelance professionals would, for the time being, still have plenty of such "specific use-cases" for an Intel-based MBP. Apple also has lots of enterprise customers locked into long-term upgrade contracts, so part of the demand for the tail end of their Intel-MBP pipeline would be fixed/inelastic demand.)