No- that private property rights are consistent with the libertarian quote above because it's voluntary.
You can argue what truly voluntarily slavery would look like in a modern world, but involuntary chattel slavery is what conflicts with principles of private property.
I'd argue things like athletes signing away future percentages of potential earnings (which was a fairly popular idea until the current NCAA name and likeness rules changed) would be one potential version.
It does not mean chattel slavery, or involuntary servitude, or even involuntary government seizures.