It's not (as far as I can tell). The closest thing I can quickly find in the transcript is the following:
Copied from transcript and lightly reformatted, but otherwise not corrected (girdle for Gödel, etc all left intact):
1:40:2x
in the fall of 1981 and I spent that time kind of studying The Works of people like bonan and girdle and bunch of stuff about neural Nets and I was that was all in kind of the can I understand foundationally how complexity shows up in the world and that caused me to um uh to
kind of um uh try and develop sort of the simplest model that might do something interesting and it
led me to these things called cellular autometer which are very simple uh systems where like tiny
programs where you just have a row of black and white cells and you just have a rule that says how to update those cells and um I started looking at those things in the fall of 1981 and
"It led me to" does not imply "led me to [discover/invent]" but rather "led me to [start studying]"
His own notes here directly state that they were considered long before he studied them:
No, of course not, it's just me parodying Stephen Wolfram every time he speaks/writes. He wrote a book called 'A New Kind of Science' claiming all this stuff in about 2002 which was widely criticised by scientists as overstating it's claims and much less important than he thinks it is, but he's been talking like that ever since pretty much.
Copied from transcript and lightly reformatted, but otherwise not corrected (girdle for Gödel, etc all left intact):
1:40:2x
in the fall of 1981 and I spent that time kind of studying The Works of people like bonan and girdle and bunch of stuff about neural Nets and I was that was all in kind of the can I understand foundationally how complexity shows up in the world and that caused me to um uh to kind of um uh try and develop sort of the simplest model that might do something interesting and it led me to these things called cellular autometer which are very simple uh systems where like tiny programs where you just have a row of black and white cells and you just have a rule that says how to update those cells and um I started looking at those things in the fall of 1981 and
"It led me to" does not imply "led me to [discover/invent]" but rather "led me to [start studying]"
His own notes here directly state that they were considered long before he studied them:
https://www.wolframscience.com/reference/notes/876b/