It's just another (hopefully somewhat systematic) perspective on a known phenomenon, though. (OP here.)

P.S.: What might be of minor interest is that this may help decide, whether it's "ROL A" (as in older assemblers) or just "ROL", etc. (as in some of the more modern ones). We may see that there is a slot for "ROL A" and another one for "ROL implied", which is a NOP. As is the case with all the other accumulator instructions. – However, brevity is still a thing. :-)

I like it as an example of inferential process; here's what we can see the chip do in response to inputs, here's what we think that must mean for its design. With the ability to go look at the hardware and many explanations of it to go look at later and see how and why the observed effects happen.