Are Hub 3s being retired?

I saw a news article today about older broadband hubs being replaced. Mine is a Hub 3 and when I went onto the page mentioned in the article to check if mine is included it says that my hub needs replacing.

Is the replacement of a hub a self-install or does an engineer have to do it?

If the hub 3s are being retired, which generation are they being replaced with?

I believe that my parents also have a Hub 3 so the same will apply to them as well.