I'm sure lots of automated scripts are involved in a product going up onto Amazon, but to suggest that no humans were ever involved in the creation of those shirts is probably nonsense, unless you have evidence to show that it actually is the case. The most obvious explanation is that a human made them, and it's not particularly difficult to believe that someone out there would make that shirt design. I've met people like that.
It's an obvious thing to do. Amazon already sell print-on-demand ebooks, allowing vendors to spam the products list with a torrent of shit at minimal cost so they can find out which bits stick. This is exactly the same principle.
(See also, in case you're reading this later and there are a lot of comments: https://news.ycombinator.com/item?id=5310567)
my verb list doesn't contain rape https://github.com/andrewcooke/pn-art-adj-adj-n-v-adv/blob/m... . i'm not sure why - i did check by eye, but i don't remember having to exclude it. however i did filter so similarly-spelt words are rejected. so perhaps it was similar to some other verb.
maybe i should make t-shirts.
anyway, this is just to say that you've also, now, met someone who makes random sentences with computers. we do exist.
"Keep calm and ripen?"
Nothing wrong with rapping.
$sentence = "Keep Calm And Carry On";
$replacements = array('Carry' => 'Other', 'Dictionary', 'Words', 'On' => 'A Lot', 'Off', 'Them', 'Us');
echo strtr($sentence, $replacements);
Once you've done that, simply use a Macro to add it to Amazon.