or you simply missed the answer on the previous pageYes, deleting an account does not revoke the tickets.I've never created a new account on a machine that had another account on it, but unless eShop does something like "Here's a new NNID. Let's wipe all old console tickets and issue new ones" (which we have no reason to think it does) it won't matter.
Don't sell a machine with CBHC. If something happens and it bricks, you can't help them. You could tell them how to install CBHC from the tiny SD you left in the slot, you might even have a Haxchi button set to run the installer, but put the responsibility on them, not you.