I don't think this is actually true for most of what people do with AI right now. Machine learning these days is something where you want strong, native machine level support for numeric programming on matrices. Possibly with GPU support. So a lisp based language wouldn't really help you much in the current environment.
If what you want is a system that rewrites itself, then you definitely want homoiconicity. It also helps if everything is one big expression.
Let's say you want to write an evolutionary algorithm that rearranges fragments of its code and runs it. More successful functions make it to the new generation. You want LISP for that.
Realistically, you could probably do this on any abstract syntax tree. But the problem is that unless your language is homoiconic, what you get back might not actually be valid in your language. So, homoiconicity gives you bidirectional support for rearranging the AST and still getting something you can read.
It's also just a lot easier to write something that looks at the code and does computation on it when that code is also data.
But, like I said, I'm not sure many people are actually doing this these days. It was popular back in the day. It's not clear that it's the right way to do things.
If what you want is a system that rewrites itself, then you definitely want homoiconicity. It also helps if everything is one big expression.
Let's say you want to write an evolutionary algorithm that rearranges fragments of its code and runs it. More successful functions make it to the new generation. You want LISP for that.
Realistically, you could probably do this on any abstract syntax tree. But the problem is that unless your language is homoiconic, what you get back might not actually be valid in your language. So, homoiconicity gives you bidirectional support for rearranging the AST and still getting something you can read.
It's also just a lot easier to write something that looks at the code and does computation on it when that code is also data.
But, like I said, I'm not sure many people are actually doing this these days. It was popular back in the day. It's not clear that it's the right way to do things.