I must be missing something as if you go from your 8000 Active to the current Active the price stays at your existing £25.32 so why not just swap to the current Zen Active? It works with ADSL in that at my distance from my cabinet my router connects on ADSL.
Zen's non-8000 packages are provided using the ADSL2+ line card in Zen's MSAN in exchanges where Zen has presence and BT Wholesale 21CN otherwise. If neither of these wholesale services are available, you cannot order the Zen product.
Zen 8000 packages are the only ones that will use BT Wholesale 20CN.
It's many years since I moved from 20CN to 21CN on Zen. So far as I remember, Zen did a bulk move of customers on 21CN upgraded exchanges from 20CN ADSL Max to 21CN ADSL, effectively giving the customer the same product but delivered over the newer, cheaper, wholesale network to minimise Zen's costs. I believe it was then up to customers to ask for a free speed regrade if they wanted ADSL2+ enabling.
I expect Zen continue to bulk move customers to the cheapest wholesale offering. Towards the end of last year, Zen installed a point of presence on their network at the handover point of our FTTC connection, so we were moved from BT Wholesale WBMC to Openreach GEA-FTTC with backhaul over the Zen network.
What I don't know is what Zen do with the customer's product and pricing when Zen LLU ADSL2+ or 21CN becomes available to a Zen 8000 customer. I suspect the upgrade involves a new minimum contract period, so it is up to the customer to request the product switch.
I wonder if a different e-mail was sent to those customers on Zen 8000 products whose service is delivered over Zen LLU ADSL2+ or 21CN, so could switch to a non-8000 product.
As has been said, 20CN backhaul costs continue to rise on a per customer basis, so these costs have to be defrayed somewhere. Whilst BT Wholesale maintain a price differential between 20CN bandwidth and 21CN bandwidth, the ISPs either have to spread the extra 20CN costs between all customers or pass them on to those unfortunate enough not to have access to 21CN or LLU backhaul.
Edit: a couple of clarifying changes only
Edited by deleted (Thu 09-Apr-15 22:39:38)