With regard to GPT-n, I don’t think the hurdle is groundedness. Given a sufficiently vast corpus of language, GPT-n will achieve a level of groundedness where it understands language at a human level but lacks the ability to make intelligent extrapolations from that understanding (e.g. invent general relativity), which is rather a different problem.
The claim in the article is that grounding is required for extrapolation, so these two problems are not in fact unrelated. You might compare e.g. the case of a student who has memorized by rote a number of crucial formulas in calculus, but cannot derive those formulas from scratch if asked (and by extension obviously cannot conceive of or prove novel theorems either); this suggests an insufficient level of understanding of the fundamental mathematical underpinnings of calculus, which (if I understood Stuart’s post correctly) is a form of “ungroundedness”.
The claim in the article is that grounding is required for extrapolation, so these two problems are not in fact unrelated. You might compare e.g. the case of a student who has memorized by rote a number of crucial formulas in calculus, but cannot derive those formulas from scratch if asked (and by extension obviously cannot conceive of or prove novel theorems either); this suggests an insufficient level of understanding of the fundamental mathematical underpinnings of calculus, which (if I understood Stuart’s post correctly) is a form of “ungroundedness”.