Thanks Noel, still trying to decide if 23 has anything I really need, but I am aware that the various alternatives have been available in 22.
I put the question to support when I did the original post and their responses told me the same without any further explanation until the latest, quoted below.

Last reply, PGM to me;
I will pass your thoughts on to the developers, however I don't think the old menu entries will return as the new Copy/Move Tracks does the same job, and they've been working on removing redundant menu options to clean things up, which is something that many users have requested over the years. To access the Copy/Move Tracks option quickly you can press Alt E, then Y, then T.

For the Kill/Erase Soloist track, it can be easily accessed by right clicking on any track in the mixer and choosing Erase Track from the Track Actions submenu.

Me to PGM;
Thanks for the response.
I agree, the menu system is in need of a complete revision and tidy-up, not sure that doing it quietly, one item at a time is the correct approach.

Will mark this thread as resolved.

Vintage