They don’t mention the length penalty that comes from wrapping around the cable or any impact of loss to fiber itself. Given the helical pattern, I’d imagine that they are adding substantial length to any distance they need to achieve. Generally you have about 20dB of loss before you need an amplifier or a terminal node. A typical number for field installed fiber is 0.25dB/km. So there’s some distance penalty needed here. I’m not clear on how you’d add amplifiers to these routes or if they are simple short hops.
Generally regular SMF-28 has a bend radius of 25mm. This is partially for loss reasons as bends below this radius induce loss and partially because bending fiber below that radius creates micro cracks in the fiber. The micro cracks can spread with time and cause the fiber to break. Given the rather large CTE mismatch between the power cable and the fiber cable, the 2 will expand at different rates with temperature, putting additional stress on the fiber, potentially leading to failure.
It’s possible to have a less bend sensitive fiber but it’s generally used more in specialty applications and not as transmission fiber. So it’ll be more expensive per km.
Along the lines of mechanical failure, it would seem that there would be the potential for abrasion between the power cable and the fiber cable jacket.
Finally, it’s a little unclear how repairs would be made. Doesn’t seem very safe to have to splice the fiber on a live cable like this.