If there is a requirement to explicitly get deleted locatables, COMPOs etc. I think the ADMIN API would be a better place than a GET in the normal API. My rationale is: with the current specs it’s clear in which conditions the GET returns No Content and that is for DELETED COMPOs. So if the contents of the DELETED COMPO are required, I would say the reason might be more for management/audit purposes than normal API interaction (CRUD), that’s why I think the ADMIN API is a better place for this requirement. Though as said before, by using the previous version the contents can be retrieved (see my previous comment).
I’m not sure why developers get confused around this, the spec IMHO is clear and unambiguous, it just needs to be read in full, and of course if there are doubts, there is a friendly community here to help out 