Considering that these passages deal with acts of war and killing, and considering that there are numerious verses scanctioning slavery and regulating the practice of slavery, I don't see that this carries the weight you want it to.
I'm not sure how much worse the American system of slavery could be than one that allows the owner of a slave to beat him to death, provided the slaves lives at least 24 hours after the beating.
The Old Testament rules were specific to the Hebrews' situation. God authorized them to enslave the prior occupants of the land that God sent them to possess, and could and did have harsh laws about that. This was a one-off situation. That theology can't be carried forward even into slavery under the Roman system.
And, it's notable that "liars" are named along with the slave traders in Revelation as among the hell fodder -- puts a damper on the theory that this was simply talking about acts of war.