The fields I mentioned previously "data about antenna polarisation, elevation, frequency, height, manufacturer, power rating, reference codes, start dates, tower type/construction and names" but really anything copied from other datasets is problematic.

The ACMA RRL database is not compatible for use in OSM, see their license terms at https://www.acma.gov.au/radiocomms-licence-data#terms-and-conditions.

I'm not sure what difference the the data being the same makes? If the same data is published by A, B, and C if it's not sufficiently licensed we still can't use it in OSM.

Wikidata I believe has a much lower barrier in terms of copyright, they are okay with copying data from copyrighted sources under the claim "data is not copyrightatable" but generally OSM sets the bar higher that if the publisher claims their data is protected by copyright we don't try to go against them.