richms:

 

Up to the retailers to do that, which IME they do tell people about when moving over.

 

I know of one instance of a person who had fibre broadband installed and he wasn't warned that his landline phone would no longer work during a power cut. This later led to a very serious situation when this person couldn't phone out during a power cut and nobody could phone him. He has since purchased a mobile phone and has plenty of mobile data.

I have been influenced by this example when deciding how to get my own fibre broadband installed.