Not being from a service provider my view is somewhat simplistic.
Telecom offers a layer 2 service called UBS, which uses L2TP between their
RAN and the ISP. Over this PPP runs. So I don't see any reason why an ISP
couldn't offer IPv6 over UBS.
Pretty much every Cisco DSL router supports IPv6. We
just need an ISP
to start selling the IPv6 transit ...
The last I knew (which was admittedly many years ago) Telecom's wholesale
DSL was a layer-3 service, with frames being routed through a twisty maze of
RFC1918-numbered routers before they arrived at the user's ISP. If that was
still the case, then surely Telecom would need to route v6 frames between
the customer and the ISP for the customer to receive native v6 service?
If there has been a subsequent layer-2 wholesale DSL service offered, along
the lines that is done elsewhere, is there not still a requirement for
Telecom to switch v6 frames from PPPoA into L2TP, or whatever framing is
used to present a user's traffic to an ISP?