Progress with LLMs would seem to support the title. The language abilities of LLMs does not seem to lead to higher thought, so there must be additional processes that are required for higher thought or process that don’t depend on language
If I had time and free use of an LLM, I'd like to investigate how well it understands constructional synonymy, like "the red car" and "the car that is red" and "John saw a car on the street yesterday. It was red." I guess models that can draw pictures can be used to test this sort of thing--surely someone has looked into this?