Facebook is building a 480 Tbps subsea cable connecting Spain to South Caroline. Some of the capacity in the form of fibre pairs and spectrum will be sold to carriers in the wholesale market. It is a 24 pair system using the latest and greatest spatial division multiplexing technology. Traditional coherent optics technology is limited to 6 or 8 pairs max.
No, Facebook is building a cable from the East Coast to South Africa and then from South Africa to India and forward to Australia. The final leg is to the US. What Tagare did is take the W shaped network and add branching units. Those branching units have not been confirmed by my contacts. The general shape of the network has been confirmed.
Actually the RTD ranges from 58.9 ms to close 80 milliseconds depending on the cable. That is assuming the end points are Secaucus NY4 and Slough LD4. Those re data centers.