I can’t speak with certainty about what is the standard process applied by UPC. I can however say that everytime I moved (brand new or old flat) a third party technician had to come and check the signal on the plugs.
This was in the regions of Gland, Lausanne, Yverdon, Neuchatel and La Neuveville.
I don’t now if it is a standard or if they check what the last person had. Maybe they won’t come to check if the last person already had the same subscription??