Good news. The guy that bought it did renovations, and was not a flipper.
He decided to be a landlord and rent it out. He kept it as a 1-family house. In fact it may have been the local council that wanted it to become condos (to maximize housing stock of which there is a local shortage). We now have a family of very quiet people next door (we think Colombian origin). Well, quiet so far. We will see when the hot weather arrives. But at least they are not smokers, have no screaming babies or barking dogs.
Already to be kind I have dug up a honeysuckle plant that sits on our border fence. I do not want it sending branches next door into their space. It seems to fire out branches whenever I am not looking so it is had to keep tamed by pruning alone. They did not request that, but I am trying to be a good neighbor in advance. Act like you want to be treated.