No, it's the Council's responsibility - back in the 1980s, they discussed allowing operators to manage their own stops, in the same manner as Hong Kong, but that would have led to a proliferation of bus stops of the ilk of the e-scooter fad. They prevented this being privatised at the time, which shows just how the quality of Parliamentarians (even Tories) has declined precipitously since then. Stops are Council property, but they need to be told that the routes have changed. Knowing how Councils are typically run, someone will have to keep an eye open for the Traffic Commissioner changing routes etc. so if whoever is off sick, or retired, or the position is vacant it may well be the case that the Council is unaware of the change.
In my own encounters with Councils, I have quoted the NaPTAN reference whenever complaining about bus stops etc. and they have always responded asking for the street address.
NaPTAN = National Public Transport Access Node - it is a unique identifier for every bus stop, stance, train platform, and possibly ferry terminal in Great Britain.