Vodafone’s 3G network has been switched off for 9 months at this point, I don’t know if customers would still be getting messaging about it. Though there was a section in the article about issues with roaming for international visitors in January:

As a result of the Vodafone 3G switch-off in January, inbound Roaming customers have been receiving text messages advising they will no longer have access to voice, text or data and emergency calling whilst roaming in Australia.

Even customers with 5G iPhones have received such text messages.