Quote - Is there a way I can delete the entire full body morph in one go without having to delete it from each individual body part??

The short answer is "No".

Using a Poser library file editor (I use CR2Builder) to edit the cr2, may be easier than doing it in the Poser Hierarchy Editor, but will still be tedious if many body parts contain the morph. One or more of the commercial editors may have a feature to do it, but I don't remember hearing of such a feature.

As you want to "re-load different version of the same full body morph", an alternative solution may be to create a delta injection pose to inject the new version of the morph into the old channels.

If the figure uses PBMCC channels (most recent DAZ figures do) you can use svdl's "SpawnCharacterP6 update" to make INJ and REM files. If not you could use "Pozers Little Helper".