The inability to develop new theory is a big deal
Without it, the models are ill-poised to make the kinds of breakthroughs one might initially hope for. They are, in some sense, limited to working within the closure of existing human knowledge
That closure contains a lot of useful things (including the majority of stuff done by most people on most days), so even if this limitation is fundamental, it won't prevent the models from being immensely useful (which they clearly already are)
But still, it does appear to be a barrier shared by all models today, and I don't think we should take it for granted that current approaches will one day cross this barrier
(But who knows, maybe The Next Model will age this post like milk)