>> I am suggesting the LLM will (effectively) call out to a knowledge engine at training time, learn everything the knowledge engine knows, and render it obsolete.
You are suggesting that the LLM would "learn" to apply the rules built into the knowledge engine. I'm not as optimistic as to think that a statistical algorithm that uses random inputs would be reliable at applying deterministic rules. But for the sake of argument, let's assume that you are correct and that we can have an LLM replicate deterministic logic and exact computation, or that we can have it be right 95% of the time. That's basically the extent of human intellect[^1]: statistical processing for most common life situations, and deeper analytical thinking for some rather atypical cases (i.e., analyzing algorithm complexity, trying to demonstrate that the L4 Lagrange point is on the vertex of an equilateral triangle, or applying logic to forecast the stock market next week or how many degrees the global temperature will raise in the next two decades).
Crucially, we are good at having computers check a proof, or simulate a system to ensure correctness, but before LLMs we were the only ones that could create that proof (by using socially learned heuristics to probe the proof space), design the system (by using knowledge passed down by fellow humans and assimilated by our "internal rule engines"), or come up with a definition of correctness (by doing a lot of inner and outer argumentation and possibly obtaining peer consensus). If we get an LLM do that as well, for most practical purposes we would have achieved AGI.
If we are there already (or if we will be, in a few months or years), the world is going to look very different. Not necessarily in an apocalyptic way, but some priorities are going to shift[^2].
[^1]: Admittedly, there is also some biological characteristics that bias our intellectual processes in a certain way, but that's next-level madness and nobody is talking--for now--about giving those to an LLM.
[^2]: If you could have at your beck and call a general intellect engine that could build entire programs and systems for you, what would you have it build?
