There was a lot of popular software that used preemptive threads, as it was the only way to make use of the second processor inside multiprocessor Macs. Some examples are Photoshop, Premiere, Final Cut Pro, After Effects, Lightwave, and Cinema 4D. See https://web.archive.org/web/20210619165728/https://www.macwo... .

It's totally fair to disagree about whether Mac OS 9 meets the stated requirements. I just don't think it's reasonable to assert that GGGP (who may have made unwarranted claims about OS 9) was actually confusing OS 9 with OS X.