The main question here is how to define whether something is a novel idea or not. I think that ideas that seem very creative or novel are still in some way constructed from ideas or concepts that were available before. (In some trivial sense this has to be true, if there were no connection to any previous thoughts the idea would be incomprehensible.)
You make a useful distinction that I would like to respond to:
“applying a known procedure to create something” versus “inventing the procedure from scratch”.
It seems to me like 'inventing the procedure from scratch' is a potentially misleading way to put it. For example you mention mathematical induction, but is it true that a human actually invented that procedure from scratch? What I understand is that induction as a method of argumentation was already used by the ancient Greeks (and probably others), then mathematicians started using it as well but at first in a more handwavy informal way, then later its usage became rigorous and conceived as a step by step procedure that allowed for a definite conclusion, but there wasn't really a single point where mathematical induction was 'invented from scratch'. I think you could probably tell a similar story about your other examples.
Just to point to one salient example: the highly creative idea of evolution was invented by Darwin and Wallace in connection to reading 'An Essay on the Principle of Population' by Malthus. Similar points could be made about the invention of calculus and a number of other concepts and inventions.
So how should we judge how creative an idea is? I don't have a good answer to that, at least not a formal one. It seems like several dimensions contribute, like inferential distance to prior thought, level of abstraction and generativity (how much new work can be done after generating this new idea). Regarding LLMs, I would say that they are already capable of generating novel ideas and that the degree to which their ideas seem creative and novel on such metrics will probably only go up over time.
Many people expect the AI paradigm to approximately AGI complete, and expect it to smoothly scale to AI that can do innovative science. i.e. the kind of science you'd need to do to develop a plague from scratch that actually kills all humans, with very limited opportunity to experiment. Or, the kind of science you'd need to solve alignment, so you could build a more powerful successor AI that shares your values.
A periodic thread of disagreement has been @TsviBT, @Steven Byrnes and some others arguing that, yes, the AIs are getting better at verifiable tasks, but they still seem to be missing some basic sauce that lets them actually form new concepts on the fly and apply them.
The AIs are getting better at "brute force creativity", where you try every single idea ever devised by Man in parallel and maybe one of them works. But there's still a kind of creativity that a) would have way higher efficiency and b) is maybe necessary for doing some kinds of breakthrough work.
On one hand, my subjective experience has been seeing AIs be able to demonstrate increasingly interesting judgement and taste in increasingly many domains (even open-ended ones). But, I do indeed still run into AIs that get confused and "just don't get it", in a way that is pretty suggestive that there is still something significant missing.
OpenAI has lately been shipping some major results in mathematics, for problems that people had previously agreed were important and hard. But, I'd heard for previous results that the proofs turned out sort of "not actually interesting", compared to how sometimes makes you go "Holy shit that's beautiful/elegant/surprising" and conveys someone is a level above you."
Recently they shipped a lot of new proofs on important problems.
I'm not a math guy. But, seems fairly important for some people with enough context to wade through them and figure out "What sort of cognition was involved here?". Do any of the proofs have the vibe of AlphaGo's Move 37? Does it invent a new concept that does real work?
I'm guessing answering this is a nontrivial task that'll involve some... archaeology? Might be cool for a competent math theorist who doesn't have a higher priority project to organize the labor. (I'm guessing the broader math community will do this on their own, but not necessarily organize the information in a way that's optimized for figuring out "is this the kind of mind that could solve its own alignment or quickly develop radically more powerful weapons than we have available?").
I'm shamelessly copying in @DaemonicSigil's quick take about this, to give some hooks for people to start thinking through.