This confuses me, why continue with old tech and not continue with upgrading everyone to fibre to the home?
A lot of those areas would also have underground cabling. Often with blocked ducts etc. Thats even more costly.
Running fiber overhead on poles is comparable cheap and a lot of that stuff probably needed a refresh anyhow.
Just look at the figures along: 1.7M VDSL lines, 300k FTTH. If you had to roll out FTTH for all 2M homes (cable, DP, civils), it would be a whole different ballpark.