Joe Rossignol, who scooped this, reporting for MacRumors:

Apple on late Friday evening added a “while supplies last” notice to its iMac Pro product page worldwide, and removed all upgrade options for the computer, leaving only the standard configuration available to order for now.

And:

We’ve since confirmed with Apple that when supplies run out, the iMac Pro will no longer be available whatsoever.

As I tweeted when I first read the news, the M1 is a hard reset on the Mac. The leap in performance from Intel to the M1 is just so great, with a massive improvement in battery life as well, the end-of-life of every Intel Mac is writing on the wall.

And if you have thoughts of selling your Intel based Mac, expect less, as a replacement that does more (at least for most models) is relatively inexpensive.