yes, if we dismantle the current system whatever is built after is post-abolition.
if you have a repeat serial offender you have to restrain them, kill them, or let them hurt people. One or two of those are obviously not acceptable, so are you going to have capital punishment or are you going to figure out a way to separate someone from their victim pool in a humane way that doesn't carry the baggage of institutional racism etc?
abolition doesn't mean you never have custody of someone, it means the current carceral system is abolished.