I mentioned whaling songs, but I could have mentioned songs about fox hunting, or songs such as 'The Maids of Australia' which promote toxic male attitudes towards women.
Keith Price said that, 'if we go down that road there won't be an awful lot of trad songs left to sing' and maybe he is right.
This thread asks for songs that are no longer heard in UK folk clubs. Personally, I would find it far more interesting to know why some songs fall out of favour. We know that social attitudes change over time. Things that were once acceptable can, with time, become unacceptable. And songs reflect these changes. So perhaps Keith is right and there will be groups of songs that are no longer deemed acceptable in the future.