Auditorium 23 phono cable for tonearm base to preamplifier connection ?

The only reason not to do that would be the inconvenience if you wanted to change cables at some point. If you're confident A23 is your last phono cable then go for it.

May I suggest you try Acoustic Revive ECI-50 contact enhancer on the existing plugs and sockets before going to irreversible surgery?This stuff is not easy to find, but absolutely incredible in its impact.
Use on cartridge pins, RCAs, power cable and speaker wires as well as digital connections. Also useful at the junction box.

I was curious to hear if anyone cautioned on the cable's single ended ground. My only concern would be that the A23 cable as supplied is blissfully quiet, i.e.; no hum, and I need to keep it that way. There was a little hum on the previous cable used. If bypassing that set of connections --(x2) solder joints, mass of RCA female, and the amp interior cable to phono stage -- induces hum, I can reverse my step. I'd just lose A23's very neat RCA assembly work.
The Acoustic Revive contact enhancer seems very interesting; I just started using that company's copper mains cable two weeks ago. That, plus a balanced mains transformer from Air Audio, (and a tonearm!) has finally dialled in my system after 8 years trying !