Update deprecation warnings in v2.4 for #2980

[MatthewDaggitt]

#2980 was created with the idea that it was going to be released for v2.4, but didn't make it.

The Changelog was updated but the deprecation warnings were not.

[jamesmckinna]

I think I'm not clear what the action to resolve this should be, and who among us should undertake the task!?
Sorry to be obtuse, but see comments elsewhere about not having enough mental bandwidth/capacity to understand these things at times... ;-)

UPDATED I think I now understand now, and have raised a PR accordingly ;-)