I'd guess the argument is that our current artificial warming will be quickly reversed by some natural process, as seen by past cycles, even though at those times CO2 appears to be a feedback rather than a forcing.

Not at all. I have no illusions that we are only a few years, or even a few centuries, from a turnaround, although, from past cycles, one is probably overdue. (If temperatures did start dropping, there would be all kinds of theories to fit it into the current meme. Kind of like the "aerosol" rationale for an earlier cooling trend during the industrial revolution.)

What I am saying is that a mechanism has been proposed that doesn't answer a very critical question. About 130,000 years ago, temperatures that were higher on average than they are now suddenly turned around and dropped like a rock. So did CO2 levels. I can think of a number of theories why temperature might drop, given astronomical or other cycles, or why CO2 would drop if temperature drove CO2 levels.

But if CO2 is assumed to be the driver of the temperature, somebody needs to come up with a reason it all disappeared to allow temperatures to begin to drop. This question has been ignored every time I bring it up.

I did notice that gbaikie's chart below seems to have been dropped right down the hole.