Not sure I understand - don't these tenants have first position liens on the properties they live in? So failure to repay their deposits will result in them owning the property outright?
You are supposed to look at the existing interests in the property before signing a Jeonse but not everyone does that. Besides there are fraud schemes that involves property owner going into debt just before you sign which is pretty bonkers.
I was in a similar position and was advised against waiting for the property to be auctioned off and try to buy it myself.
Note: outside of a few neighborhoods, most apartments in Korea don't really appreciate in value. People want to buy new.