I don't know why something so basic can go on for 3 pages. Oh wait, yes I can, because Sunfish keeps dragging it out.
If an airport operator is unable to respond, chooses not to respond, doesn't get the email, doesn't respond quickly enough, or if ASA has the incorrect contact information, or if the owner has only updated the Country Airstrips guide, then it is not logical for ASA to remove the airport from the maps, but rather mark it as unverified.
Makes perfect sense to me. In the case that an airfield has been sold and new owners decided to bulldoze it and it's listed with a "U," there is no onus on ASA because the pilot requires "written permission from the owner" / PPR to land anyway, so the onus is on the pilot to make the decision to land there.
Edit: Believe me, CASA take PPR and written permission very seriously, should the airport operator complain to them. I know this from personal experience. Always make sure that you have written permission from the operator and not someone that you believe may represent the operator or speak on behalf of the operator, unless you have something in writing to verify this.