Yes, best practice would be that, however, if you were to look at any demarcation point, either outside, or inside by main demarcation points, you will find many unused tap outputs that are not terminated at all. (most if accessible will just have unterminated locks on them)
So no harm..these signals are in the low mW to high uW range, not much distance to broadcast with those levels. (though of course with a high gain antenna
whole different story)
There was another poster who was worried about taking the portal coax off and connecting it directly to the TV RF input..again no worries (unless the signal is a over +50dbm..but most are at -10 to +10 dbm..( I highly doubt anyone would have levels that high)
The RF input section on most TV's in use today can easily handle those signal strengths.
Just some background information on me, because I realize I am new here.
I am a SAIT Broadcast Electronics Grad,(87) worked in the Cable industry for 13 years (Mostly internal building design) I have installed and set up many industrial building with cable systems (CCTV, LAN and CATV)
My (new) existing job has me taking care of a campus of 6 building and over 2500 cable drops..
I've been here for another 10 years on top of the previous 13..
(I'm not sure if that qualifies me for a "Cableco tech" but...