OK to understand it we have to go back. and look at arcitecture of the network and realise there is a relation between a fibre and the hardware used to supply a connection. As an ex VM customer I assume you know the differences between EuroDOCSIS 2.0, 2.1, 3.0 and 3.1. (different hardware for increased speeds).
As each hardward comes along it expands the bandwidth of the existing network with VM it was more complicted due to the tech involved, multiple node splits etc. It was all hardware related.
Similarly with openreach using GPON bandwith expansion was achieved via hardware changes, initially at 2.5Gb per fibre up to 10Gb per fibre asynchronistaclly. They have been there for about the last 2 yrs, this is how Openreach can offer 1Gb connections to ISP's presently.
What the Nokia hardware you've referred to is the ability to offer 10Gb synchronous connections with a hardware upgrade.
Back in 2014 it was proved possible to transmit 43Tb/s over a single fibre. Article HERE
Where I think you are becoming confused is the difference between synchronous and asynchronous. Asynchronus gives a lower upload speed to download speed ratio which is what Openreach is using at present for retail connections. The new Nokia hardware will lift that where they will now be able to allow a synchronous (i.e. equal up/down) connection.
