Interestingly enough, most of what I've read place the P/H boundary at roughly the end of the last ice age ~10,000 years ago -- give or take.
The Toba eruption obviously created challenges for Man and beast alike, maybe moreso than the P/H event, but the PTB chose a later date for whatever reasons.
BTW, the "Pleostocene" threw me for a while til I discovered it was a typo from YOUR article -- FWIW.
I've always had problems with the way these periods are named. I went to some effort once to try and learn the exact dates of different periods until I realized (for example) that the Neolithic occurred at different times in different parts of the world. I think that's stupid.