A different contractor installs the conduit, and the issue of plenum or non-plenum spaces may not have even been considered. There's a technical term for this. There is also a recent increase in the introduction of riser-rated cable. Riser rating is only one step below plenum. Riser-rated cables can go between floors vertically, without a conduit.
Many video cables are now available in riser ratings.
Even multipair analog audio snakes are manufactured in riser ratings. Misinformation is floating around about riser-rated cables, though. They can go between floors without a conduit, but they don't stop the requirement for fire blocking between floors. The fire blocking can go right around the cables, so you still have to put that in. Next month we will look at starquad cable designs. .