Weird that this is news. Intel has always improved their yields by selling defective CPUs. https://www.tomshardware.com/pc-components/cpus/intel-reportedly-says-it-boosted-yields-by-selling-what-would-normally-be-scrap-or-low-expectation-cpus-customers-more-willing-to-accept-lesser-chips-due-to-overwhelming-cpu-demand
In the 1990s: They’d fab 80486 CPUs onto a wafer. Then they’d test them.
If they showed no errors at 66 MHz, they’d sell them as 80486/66’s. If they showed errors at 66 MHz but were clean at 33 MHz, they’d sell them as regular 80486/33’s.
If the math processor part of the die ran errors, they’d burn it off with a laser and sell the result as an 80486SX. If the CPU part of the die ran errors but the math processor section ran clean, they’d burn the CPU off with a laser and sell the remnant as an 80387 math coprocessor. If both passed tests they’d sell the combination as an 80486DX.
That way they got 80486SX, 80486DX, 80486DX2/66 and 80387 products off the same die, where all the lower spec products were just the high-spec rejects.
(Tesla does the same thing with batteries: Cells which don’t reach the quality control requirements for EVs are recycled into Powerwalls so they can get extra revenue by selling their rejects)