The M1 laptop at a quarter the price is faster than the maxed-out Intel-based iMac Pro. Not for everything… I do streaming using software x264 encoding and can set the quality levels way higher on the iMac Pro as it's native and 18 cores (the laptop's running OBS in Rosetta and has 8 cores, four of which are efficiency cores). But for some things the laptop's already a bit faster, consistently, right now. At a quarter of the price.
I'm guessing their experiments with scaling up what's in the initial M1-based Macs to more power vs. just maximum efficiency (for instance, a desktop that doesn't need to get 20 hour battery life and can actively cool itself) are turning out so shocking that they know they've got to kill the current product line, immediately.
I bought my iMac Pro in June 2020. That's a little over half a year ago, and I'm still frustrated that they took my money knowing they've got this in development. It's a good thing it has such a nice screen and still has plenty of use, but it's going to be absolutely decimated by what comes out next. It's pretty well decimated now by my little laptop if you count how much energy is wasted, and how for certain tasks the giant 'Pro' monster absolutely cannot keep up with the introductory M1 models running native code, at a quarter or an eighth of the cost.
There is no WAY they can keep selling their current line. Right now they shouldn't be selling anything that isn't an M1 or some other Apple Silicon.