Any one particular cable might not move often, but if a telco owns N bucket trucks it's a safe bet that about N cables move every workday.

Telcos are notoriously secretive about the location of their fiber. They even got most state legislatures to exempt it from state-level FOIA laws.

All cables? Everywhere in the entire country? Accurate to the centimeter level and updated on the hour?

Edit: This was flippant, but the real issues are: any map you get will be incomplete and obsolete almost immediately and cables move and sway in the breeze.

OpenStreetMap supports annotating poles and theirs cables. It's common for power lines (local and long distance). There are also annotations for communication lines (https://wiki.openstreetmap.org/wiki/Tag:communication%3Dline).

There are also public and proprietary "aviation obstacle" databases across the world.